Can I used gifted funds for my next buy-and-hold?

[Joshua Hollandsworth]

For the first time, I have found an investor willing to help fund my next deal. I am so excited! However, I have no idea how to properly borrow these funds, and I want it to work out great for both parties. Here is how I think the deal would work best- I borrow 15k to purchase a 50k duplex using a conventional mortgage (30 year fixed). I then refinance the property quickly to give the investor 75% of his initial investment. Then, I either repay this investor for the remaining 25% PLUS interest for the original loan amount. Or, I refinance, give him his 75% and give him a portion of monthly earnings. I have not a clue how to legally borrow funds for this deal and protect both parties. I want to get most of the borrowed funds back to the investor immediately. Real Estate has been very rewarding thus far. Any advice, or criticism would be appreciated. Thanks!