Make sure utilities are available, and that you have tap fees included in your estimate, as well as engineering (site plan), architectural plan, and other bits you might need to consider for your market (landscaping and costs of sale, for example).

Not a book, but Bill Faeth has a lot of free, good content on his site and YouTube videos.

I'd like to not "find out the hard way" if one of these sites are not a good match for me.The ones I'm considering are Propstream, Property Radar, ListSource, and PropwireSomething to note, I am looking to return to doing some wholesale deals, using criteria such as absentee owner, out of state owner, tax delinquent, vacant, liens, and pre-foreclosure..

Have been on bigger pockets a while, but havent made full use of the site. 

I flew there and walked the house, looked pretty turnkey rental grade): $1029 GFCI outlets, downspouts and guards, drywall, paint, bathroom vent$4615 (new AC unit since unit was stolen before tenant moved in, didn't file insurance claim because didn't want my premium to go up) $600 (water line, gas line, P trap)$60 lawn mowing$112  thermostat repairMy opinion is that Class C is better for local investors who are on site and know how to do repairs and self manage.

They'll be ok with slower speeds, just for browsing and streaming.For routers and modems, just make sure you go with name brand devices and check reviews on tech sites.

You will want to insure a number of things as an MTR landlord: your interest in the building itself (owner's policy), your contents (owner's policy), your interests if a renter or guest is hurt on-site (landlord policy), and possibly flood, wind, lost-income policies.

Thanks @Iris OlivasI did some searches and ended up on a site that provided state by state listings of Private Lenders some of whom did 75k and up. 

Evaluating deals on this site will help you understand expenses, income, and financial statement.

So a community of these homes could definitely provide an affordable downsized housing option for active seniors (independent living style) - especially when you provide amenities on site, which will be required if you want to compete with other independent living style communities and apartment buildings.