Home Quarantine Planning
Situation
Here's the situation, you or a family member have been in contact with persons known/suspected to have COVID-19, or showing some symptoms associated with it.   After calling and speaking with your doctor, your level of concern is such that you decide to self quarantine, isolate yourself at home from each other as best possible, and monitor the situation carefully.
"Quarantining yourself at home means staying at home and avoiding contact with others if you have developed, or been exposed to, an infectious disease, until the infectious period of the illness is over, or until you know that you have not contracted an illness to which you have been exposed. Quarantine helps to slow the spread of infection across a population"
Now with this situation in mind what can you do to minimize risk to yourself and people living in your home?   Let's discuss, plan and prepare!


Get everyone informed and on-board
Make sure everyone in the house understands this and takes it seriously.

Q: When is someone infectious?
A: CDC - The onset and duration of viral shedding and period of infectiousness for COVID-19 are not yet known. It is possible that SARS-CoV-2 RNA may be detectable in the upper or lower respiratory tract for weeks after illness onset, similar to infection with MERS-CoV and SARS-CoV. However, detection of viral RNA does not necessarily mean that infectious virus is present. Asymptomatic infection with SARS-CoV-2 has been reported, but it is not yet known what role asymptomatic infection plays in transmission. Similarly, the role of pre-symptomatic transmission (infection detection during the incubation period prior to illness onset) is unknown. Existing literature regarding SARS-CoV-2 and other coronaviruses (e.g. MERS-CoV, SARS-CoV) suggest that the incubation period may range from 2–14 days.
How long before the virus starts to become inactive?

Critical points to know are that COVID-19 is currently believed to only live about 3 hours on porous surfaces if not disinfected and washed away, it will become inactive over time naturally.   It can live approximately 24 hours on cardboard, and up to three days on hard surfaces like glass, metal and plastic; so important to wipe those surfaces down regularly with a disinfectant.  But even if not disinfected, the virus is becoming increasingly inactive and posing a reduced threat over time.   So time itself is your ally.  *Update - a lot of research being done on this quesiton, here's one report:  https://www.journalofhospitalinfection.com/article/S0195-6701(20)30046-3/pdf
Lower the dosage
Lessening your exposure, limiting the amount of virus that invades your body, gives your immune system more time to mount a counter attack to protect you, reducing your symptoms and severity of infection.

Isolate
If you have enough room for everyone to sleep in separate rooms, do that.  COVID-19 is shed from a persons breath, cough/sneeze, so stay away from others in the house, and wipe surfaces with disinfectant often. Practice all the tips, like wash hands often, don't touch your face, etc. from the CDC.   Infected or sick person should wear a face mask (ideally N95) at all times when they spend any time in commonly shared areas.  In the seclusion of their own bedroom, the mask isn't necessary, but they will be shedding the virus from their breath.  Stay out of their quarantine area, and expect them to be isolated for 10 days or more.
If you must go into the quarantine area, always wear an N95 mask, eye protection and gloves (ideally nitrile or other medical gloves).  Treat any clothing, and personal protection equipment (PPE) like gloves, eye/face shield, and mask as contaminated.  Disinfect or set them aside for possible reuse if you are short on PPE, otherwise consider sealing in a plastic bag for a minimum of 3 days.  Wash hands thoroughly before and after.

Picking up mail & packages
Talk with neighbors at a distance, at least 6' radius is the general rule.  Advocate talking to strangers through an intercom system or through a door for safety and security.  Wait for your mail delivery person to leave or be on their way away, before thanking them.   Pick up your mail with gloves on, and take it immediate to a designated location (like the garage, or a table/area) to process it.  Open it immediately with gloves on, and dispose of all junk mail and packaging immediately.   Carefully remove the contents of packages without touching it (if possible).  If possible just leave the items sit for 3 days, as this is about the longest the virus can remain active even on hard surfaces.  It can be detected and active for up to 24 hours on cardboard, but the packing tape and plastic labels may keep it active for up to 3 days.  If wearing nitrile gloves, wash hands with gloves on, then remove gloves and let them dry, then wash hands again.   If the delivered item is needed for immediately, disinfect the packaging, because most packages are packaged and delivered within the 3 day hazard period.  Contents inside packaging is safe as it was sealed many days, weeks or months prior.


Wipe it down
Clean up after yourself as best you are able.  If you are already sick, you have the infection, cleaning helps several ways, most importantly to reduce the chance anyone else in your household gets infected.  Disinfect the hard surface areas you are touching most often, this includes your cellphone, water bottle, box of tissues, keyboard, remote control, light switches, doorknobs, etc.  

Laundry
Do laundry in a machine with warmest appropriate water setting, ideally hot water and detergent you routinely use.  Ideally have everyone put their laundry in the machine themselves, but if taking care of others, wash your hands/arms carefully after loading the machine, and wipe down the machine while it's running.  Consider laundry that has run a full cycle to be clean, dry as you normally would.

Bathroom
Try to not share bathrooms either, unless necessary.  Everyone should have their own towels, at least two towels, and alternate using them.  Hang them up, ideally in full sunlight, or someplace where they can dry out as much as possible between uses. If you must share a bathroom only touch your towel.  If you have only one sick person, let that person have exclusive use of one bathroom if possible.   They will need cleaning supplies to keep it and their immediate area as clean as possible.  Wash your towels often.   Close the lid before you flush.  

Sleeping
If possible everyone should be sleeping in different rooms.  An errant sneeze/cough, or even just breathing expels and sheds the virus on surfaces all around you.   Your bed partner will almost certainly make contact with the virus and inadvertently touch their face (eyes and nose most vulnerable) and become infected.   The virus will likely become inactive after just a few (~3) hours, so may not be necessary to wash bed linens more often than normal as long as they are only used by the sick.
Cooking & meals
Have someone with no symptoms (if possible) cook meals and put them in separate containers for future use. Wash hands before, during and after food prep.   When using the prepared food, reheat food to above 140ºF before eating.  Naturally the infected person must eat in the quarantine area.  After use, all contaminated utensils should be washed immediately.  Keep a pan of disinfectant near the sink to dip dishes into after cleaning, then rinse and set aside to dry.  Alternatively you can wash dishes in very hot water, or spray with disinfectant, then rinse before letting dry.
Box of tissues
Everyone gets their own box of tissues and should keep it handy.  Make every effort to cough or sneeze into a tissue, and throw it away immediately, then go wash your hands.  Your body may be fighting off allergies, normal cold/flu or COVID-19, it doesn't matter, take the extra precautions just in case.   
Medication
Stock up on cold/flu meds and give the sick person the medication and let them self medicate if possible (not a minor).   If you must touch the medication or assist, be sure to thoroughly disinfect the bottle/box/device before and after you touch it, and wash up immediately after contact.  Wear PPE, (mask, gloves, eye/face shield) if you must get close to them.  Clean, disinfect and set aside your PPE after use; ideally rotate PPE every 3+ days, to maximize its usefulness, during this time of limited supply of PPE.
Entertainment/exercise/stress
It is important to occupy your mind with something productive, and stay healthy by eating as healthy as possible and exercising.  Stress is natural, if you are having difficultly coping with stress read this and let someone know.
Check yourself
If sick, take your temperature twice a day, once in the morning and again in the late afternoon, and write this down.  Also know the symptoms and keep a journal of them.  Call your doctor if/when necessary if condition worsens; know these signs and when to call.
Pets
The CDC has an excellent page on caring for pets/animals during this coronavirus pandemic.  The bottom line is there is much they don't yet know, but there is no known cases of transferring the virus to or from pets.  Some places I've read that you should wash your hands before and after petting your pet.  Certainly if you are sick and known to have the virus, steer clear of your pets if at all possible.  One concern is the possibility that the virus will attach to their fur and they will spread it around your household or areas you allow them to wander.    Here's the CDC's list of key points:

Lay off the sauce
With so many people staying home now, you can expect more 'domestic' issues and violence.  Alcohol not only impairs judgement, but it makes you less likely to follow all these new procedures and guidelines, your health and sanitation will suffer.  Plus you are more likely to be injured or unable to help others in an emergency.

Air it out
Open a window, turn on a fan or create a cross breeze to have maximum circulation of air.  The fresh air will dilute and help remove any virus in the room/home.  Be careful to not have air from a contaminated area drift into other areas of the home.    

Let the sun shine in
UV light cleanses as well, it inactivates the virus, but at an unknown rate; so don't count on it.  Sunlight and fresh air help most everything, including a pandemic.   Weather permitting, it is a good idea to get outside yourself and the infected person as well (wearing a mask), as possible/practical.

Stay in touch
Maintain good mental health.   Use this down time to read some good books or learn something new.  Be as productive as possible, and know things will get better.  Communicate regularly with others, and check on the sick even if you are not.  If someone is sick, use all precautions, keep a distance if possible, wear a mask, wash before and after, etc.

Worst Case Contingency planning
So if you are the one that was in contact with someone you later learn likely was infected, you might want to quarantine yourself not just from work, but from your family at home.  Much of this discussion above is about that situation.  But what if your children or spouse get sick?  Learn where the local hospitals and drive-thru testing locations are; go alone, so you don't infect anyone else riding with you.  Wear a mask, if you don't have an N95 mask, wear a ski mask, or anything to reduce the possible shedding of the virus from your lungs.  Make sure your will is up to-date, and plan for if you are hospitalized and are incapacitated.  Find someone that can watch your kids if you both have to go to the hospital.   Seems like most people do recover  from this within a couple weeks, and the very few that have major complications, require a ventilator or worse, the whole process only takes a few weeks.   

Conclusion
If you have better or more accurate information, please post it here in the comments, along with any references; please help us make this as accurate and helpful as possible.
I will update this topic as new/better information becomes available.  Humanity has endured through many plagues and pandemics in the past.  Today, more people have died due to the seasonal flu than have died due to COVID-19.  With a little knowledge, and inspiration, you can not only survive if you get this virus, but you can help and live with others (if you must) that have it.


References:
Contact the NH Bureau of Infectious Disease Control: 3/4/2020www.dhhs.nh.gov