Before you start scouring for deals, keep in mind that owning rental properties is time-consuming, expensive and fraught with challenges, and many investors lose money. You will want to avoid falling into one of these common traps.

• Mistake 1: Confusing a cheap deal for a good deal.

It is true that you can buy some homes for ridiculously low prices—but that doesn't mean you can rent them out. Homes in deserted subdivisions aren't any more appealing to renters than they are to buyers. The same is true for less-attractive properties or those in less-desirable school districts.

Investors from the San Francisco area often look at the Sacramento market assuming they can get Bay Area-like rents, and end up overpaying, says Robert A. Machado of HomePointe Property Management. He uses several resources, including the website FinestExpert.com, to estimate rents. Other experts suggest canvassing apartments nearby to see not just their rates, but whether they are offering special deals, like a couple of months of free rent.