Good ideas, but I think it is easy to underestimate the work involved in rental property (finding renters, collecting rent during bad times, and maintaining the properties).
I have a few friends that did this, some successfully, others not so successfully. The ones who liked it did a lot of the upkeep work and property improvements themselves (one started out as a roofer, the other was an HVAC guy).
OTOH, it can be a headache if you are a working professional. One of my friends who did this was a doctor, who kept his old house when he moved to a new one. I think he was inspired to do it by our mutual friend (the roofer). But he began to hate it after a while, because of all the extra offhours work associated with it. And then his renter developed terminal cancer and could no longer make payments, but he didn't have the heart to evict him...
RE: Wen Sell