How everyone profits from investing in rentals.

[Vince Custode]

My girlfriend and I want to begin investing in real estate. She just recently became a real-estate agent full time and I have a full time salary job as well. We have become interested in investing in real estate and want to start somewhere between live-in flips and fliping single home rentals. The problem is that we don't have any large funds saved up to begin investing and we are both rebuilding our credit at the moment. We have recently entertained the idea of bringing in an investor to help jumpstart our goals. The question is... how could we profit and the investor profit after the property has been renovated and starts being rented? We understand better how everyone would profit in a situation where the property is sold after being completed, because everyone would just get their cuts after the closing. But in the occurrence where the property is intended to be rented instead of being sold, how would everyone make a profit? Is it even possible to accomplish this? If so what are some possibilities? 

I hope I have given enough information as to our questions so that they are understood.