Anyone in the rental property game?

[PocketElevens]

Ive been considering investing in a rental property for a few years now. Even though mortage rates are very low there seems to be no shortages of renters, and no matter what happens to the market, 25 years from now when the house is payed off and im ready to retire the property will be worth much more then it is today.

Im having trouble coming up with a plan since I hear so much mixed advice.
I know someone whos bought there second income property, all they do is go for a cheap house near a college with many bedrooms. The place isnt in great shape, but they really dont care since the students dont and you can rent 6 bedrooms out for $400 each.

Other people have preached the more units the better. Ive seen some houses that have been split into triplexs and it usually means cheap appartments. Cheap appartments can attract undesirable tennents.

Others say get a nice house, charge high rent and look for a good family. The price of the house will atleast double in 25 years. If you can sit back and have them pay off the mortage + a litte extra for repairs you'll have a nice chunck of change at retirement.

Anyone have experience with this? Any feedback would be greatly appreciated.