Theoretica, this is not a game for you. This is a game for the well-heeled who don't mind seeing 7 figures come and go.
If you want to rent as a family-business thing, get well-managed condos in a good location, preferably nearby. The tenants will be better and more stable, and your maintenance issues will be simpler. Non-palatial condos will be a good bet for a while, since we'll have more renters for a while, and when they pull themselves back together and try buying again, more will aim low. It's important to do this in an area that's pretty mature and built-up already, though, because otherwise when the housing market picks up again, you'll be competing with lots of new condos nearby.
Also, do the credit, online court, and national background checks. I can't stress this enough. Lots of applicants look like perfectly nice people, have jobs, etc., but have bombed-out credit or trouble paying even modest credit-card loans. (And some have worse problems.) If you don't check out your tenants and they later do something criminal on the property, you may wind up with some liability.
Also also, cheap is not cheap. I agree with the pp who said foreclosed homes will generally have maintenance issues. Some of those homes will have structural issues, too, since "foreclosed" doesn't necessarily mean "borrowed $600K while drunk on credit". A lot of these homes are in poor neighborhoods and have 60 years' worth of deferred maintenance.
Finally, unless you're in an area with nice transients (like college towns) keep in mind that this home-rental thing will probably be a fairly short-lived phenomenon. Most people outside major cities still want to buy homes, because if they're not buying in bubbles, and they can swing the maintenance, you really do build up the equity. (I've owned since 2000 in a modest kind of market, rental and primary-residence, and even with all the economic problems I'm about $100K ahead of where I was then.) So when the pendulum swings back you'll find it harder to get good tenants into houses. Apartments, no problem, but houses -- not so much. You can always sell when the market picks up, but you'll have some substantial rehabbing to do. Rental properties take a real beating, even when nice tenants are in there.
I wouldn't do Section 8. The potential headaches, liability, and property damage are, to me, not worth the couple-few hundred a month. There are decent people on Sec 8, but not enough.
I've been very lucky, renting for the last 7 years. I've had grad students, professors, and postdocs, and on the whole they've kept the place beautifully. Even the bad boy was a Johnny Stecchino kind of fella, kept the place squeaky clean, paid on time, and emailed me promptly with any maintenance issues. But that's really a factor of location -- the property's a walkable mile from a major research university, on a pleasant-enough student-apartments strip. I've also had responsible condo managers. Even so, I had one leak that could've set me back tidily if the owner of the unit downstairs had been less kind, or if the tenant there hadn't also been a decent & cooperative guy. Am I making millions? No. After mortgage/taxes, assoc fees, and repairs are paid, I figure I clear about $50/mo plus some on taxes. Essentially the tenants are paying my mortgage; that's the payoff.
As another landlord said, landlording is a way to get rich slowly.