Then get it notarized and recorded at your county recorder’s office.

As far as what is fair, you have to sit down with your investors/partners and decide what is fair, write it down, sign it, and notarize it (optional).

Third, a safe method is to have the owner sign a "memorandum of contract", have it notarized, then file it at the recorder's office.

If want to sell the property, would I get into any problems with the title insurance company such as them requiring an affidavit from the previous investor or requiring another notarization by a title insurance company appointed notary?

I need a real estate partnership agreement sample or someone that can guide me through it, my plan B is hring an attorney that can do it and notarize it all at once, but I though this option might be easier and more educative.Additional Details if necessary:I'm willing to put all the man-power, that is, managing the job.

2-3 family houses, renovated, rented or not are flying off the shelf. 

Once the lawyer has checked it, have each of you sign it and have it notarized.

I needed to wire the funds over and get a document notarized and sent to them and within 3 weeks I had a title in my mailbox.

They don't need to be notarized but they do need to be dropped off at the title company / lawyer.

Mother did write a letter stating that her son isn't apart of the house and it is notarized.