Whether you are forming a limited partnership (LP) or a limited liability company (LLC),  you need a contract between the owners of the business that  will serve as a blueprint for everything to follow.  In an LP, this contract is known as the partnership agreement.  In an LLC, the contract is the company's operating agreement.

In general, such agreements should address six distinct issues:

1. Formal formation of the of the business entity with the state.

2. How the business is to be managed.

3. Capitalization of the business (initially and in the future).

4. How profits and losses will be shared.

5. The manner in which ownership interests may be transferred to others.

6. Winding up of the business upon its completion.

While the details of Step 1 (forming the entity) will usually be dictated by state law, the parties have an enormous amount of flexibility in the other five areas. Careful consideration needs to be given to each in order to make sure that all of the parties are "on the same page".