I'm not sure how much you may have to invest in a time or capital sense, but with this as long as you have the time you can pretty much get around not having to use any of your money or credit to pursue this opportunity.
So it's called Wholesaling, I'm not sure if you're already familiar with this but it's basically reassigning properties for a seller to a new buyer that wants the property. It's that simple (once you find a seller and buyer of course) but that's where your time would need to be invested. There are databases online that give access to the type of properties you'd be looking for to help make the job easier and you could also drive around and see houses for sale and inquire about those if they're for sale by owner.
There are many key things to look for when dealing with real estate but it's worth it if you can invest the time. You could earn anywhere between $5-10,000 when closing deals and you'd do that 2-3 times a month once you get the hang of things.
I hope this helped!