James, It's my opinion that If you don't have the saved cash for a down payment you likely shouldn't be investing in real estate. That being said there are a few avenues that may work for your situation.
Most people who get into real estate with "no money down" start by wholesaling. This method allows you to put properties under contract with little or no money (Earnest Money and/or Option Money) then markup and sell the contract to an investor who closes on the house. You make the net margin (via assignment fee). There are plenty (too many) resources on the web that teach wholesaling, They all make it look easy and promise $10k checks every week. The truth is, wholesaling is tough, but the rewards can be great. One deal may net you upwards of $10k, but often it is several small deals that help generate that extra income.
The second option that came to mind may require some money on your end. Consider subject-to investments. In this instance you find a homeowner/seller who is behind or about to be behind on their mortgage or underwater and you offer to purchase their home home by catching up their mortgage. In this case the owner sells you the home, but their name remains on the mortgage. You pay the monthly mortgage. If find the right property, you can purchase the property for a few months back mortgage payments, put it minimal repairs, then rent property for an amount more then the monthly mortgage payment. Thus netting monthly cash flow and minimizing cash outlay and risk. My example is somewhat oversimplified; it's a bit more complicated just finding someone behind in their mortgage, but these deals exist and this strategy may be worth researching.
I hope these ideas help. I know when I started out, I bought duplexes with FHA loans; lived in one side and rented out the other. After two years (had to show rental income) I would buy another. The strategy has severed my well over the last 14 years. In fact I recently moved into one of my duplexes while I am renovating a historic home for me to move into near Downtown.