My #1 advice is to buy a time machine and buy property in 2009 and 2010.
If that option is not available to you, I think a duplex or 4-plex would be a good start assuming you could live in one of the units and manage the rest yourself. Try to find something without an HOA and HOA fees.
Make sure you have about $10,000 in the bank for unexpected disasters like a roof or a sewer collapse. Otherwise yeah it's pretty much about the numbers.
except that some neighborhoods are so much trouble, even with good numbers it isn't worth it to me...
if nobody without a meth habit or felony convictions will live there, good luck getting that rent!
I agree with this which is why I avoided Antioch and Pittsburg even when returns of over 10% on 100% cash properties were available. A decent part of town with good tenants is preferable to higher returns in my book.
If your father is in a rental business and is local, ask him. As someone just entering the field you might make basic mistakes that cost you money.
Cost of ownership (mortgage / insurance / taxes). Cost of maintenance... is the house really old? Just repainting and changing the carpet is not expensive, but if you have to get into electrical, plumbing, roof, etc... it gets pretty expensive even if you get to write some of that off.
Can you financially handle not having a renter for an extended period? Important thing to consider if tough times arrive.
I have a friend who invests in a duplex in a not so good area of St Louis (near Wash. Univ.) I would put it, eventful. I believe one of the tenants got arrested in the duplex. Also, in that area, it's kind of an old town. So, you may have to spend more on maintenence if you get a old house. St Louis is not expensive but not cheap either. All in all, I believe it is not easy to get a higher than 10% return rate for cash investment. For starter, I suggest to find a relatively safe area and do strick background/credit checks so that you don't run into a bad tenant who will leave a bad taste in your mouth.
Like E-man said, you need to define you objective before anything else. Roberto and Iwog are looking for cash flow right now, I'm looking for faster pay down ( I only take 15 year mortgages) to defer some of the tax obligation and cash flow until I'm retired.
What you can afford will dictate your tenants. Problem is what you can afford might be affordable because there is a glut of similar units. Take a lot of time to look at what rents and what sits. There can be sharp stratification in an area, with a shortage of some types of rentals, but a glut of other stuff.