I had 5 rental properties. Aside from being a royal pain in the ass and a crazy amount of work, they were great for my taxes and paid for themselves and my home.
I never paid a dime for any of them. We used the equity in our home to buy the first rental and bought well. We used the equity in that one to buy the second, and so on.
The only drawback is that all the stacked second mortgages tie up properties when you want to sell, so it's very important to use the same bank.
You also won't have the equity in your home available for a loan, but I've never taken a home equity loan in my life, so it's a non-issue for me.
If you want to really learn a lot about being a landlord and hear about things you'd just never think about, get on ebay and buy the Carlton Sheets course. It's full of very valuable info and will head off a lot of problems you'll run into in the future.
You'll also want to learn how to search title at the courthouse so you can make sure properties you're interested in have clear title before you act. Otherwise you'll spend a lot of lawyer money for nothing and waste a lot of valuable time.
Good Luck, man!!!