Great discussion, glad there are others out there looking at solar
To start your journey get your last year's electric bill and get a calculation from
PVWatts Calculator of potential power production and to size your unit (This is a government site where you can select historical solar radiation data from near your home, I used data from under a mile away) I paid just under $2500 per KWH for my top end system.
As far as panel placement, put as many as possible on the southern exposure and the rest on the east side as afternoon storms make the western exposure less productive ! Every solar installer will ask for your electric bills for the last year and be able to project how many panels will fit where by using Google Earth. My installer, Unicity, provides a cell phone (not WiFi) based system where I can look at each panel performance and daily usage and production data. So far I am selling a little more back to SECO than I am using.
Energy Sage is an excellent site to learn about the different panels available. I purchased the most efficient panels for Florida Panasonic with EnPhase digital inverters. One caution, don't have Energy Sage send contractors to you because if you deal direct your price may be cheaper. I found excellent contractors thru the Panasonic Site which lists their best contractors.
On the question of payback, I did not consider the lost investment cost of my purchase. Nor did I figure anything for maintenance as my warranty covers product, labor, and roof penetrations for 25 years. My thought was that I am locking in the cost of electricity and figure my next car, if I have to buy one, will be electric. Unless your system size is very large (I think over 6.2) you do not have to carry any extra insurance. Your homeowners should cover it.
Also be aware that the 30% tax credit is scheduled to be reduced in 2020 not eliminated. My understanding is that resale is higher but I do not plan to care about that 20 years from now.
Thanks Jimbo120