My answer to What is your best advice for maintaining healthy co-founder relationships?
Answer by Ken Larson:
Develop and execute an operating agreement.
It should be a simple, straightforward document you and your prospective partner(s) can draft yourselves, addressing such matters as % of ownership, how revenue will be distributed and other general matters, as well as who can commit the company in the form of credit cards, who signs checks on the company account and other administrative matters. Buying out a partner should also be covered as well as adding new members if the need arises down the road.
I have seen many enterprises fail or go through terrifically hard times due to lack of an operating agreement. The parties should sign it after a review by a lawyer. It should then be notarized and made an official part of the company file. You can download a generic operating agreement at the Box Net “References” file in the right margin of the site linked below:
You can feel free to borrow from the sample or supplement it as you see fit. It is fairly comprehensive in order to cover most business situations and there may be elements of the example you feel are not necessary.