As of right now, I am just trying to gain knowledge from books and what not before I dive into anything.

@Eric Forcier, a lot of times boarding houses housing ex cons, ex drunks and what not fall under a protected class.

They will act as my "boots on the ground" to help keep an eye on area trends and what not. 

I did look up 1 Roseville zip code and there are 3,251 apartment units so there must be an excess of 8+ unit mulit-family as there is very little turnover on MLS.  36% of housing is Non-owner occupied in Roseville so there are a lot of rentals, but I imagine a big spread between single family rentals and large multifamily.I'm like everyone else on BP, looking for the best return on investment, securing retirement as you say, and trying to do it intelligently, and help others along the way too.The purpose of this forum was to see what areas other investors are seeing, where they are focusing efforts and whatnot.  

Cluster flies can come out of attics and whatnot in Spring and Fall.

This means 99.9% of the people on these lists said "NO" to you. 99.9% of people on all your lists are NOT motivated.So yes, you CAN target foreclosures, absentee owners, and probates and whatnot, BUT those people are NOT motivatedSo What I am telling you is not a matter of opinion.

I also ask for references as well to validate employment and whatnot.

I also go up once a month to check on properties and also do closings and whatnot at that time at well.

@Brian Bradley  one of the all time greats of what not to write... was some guy back east talking about how he paid off fellow bidders at courthouse steps..

As the land lord, you might also need to consider dump stations for grease and what not, clean restrooms/portapots, sitting area and someone to keep trash picked up.