You can pay a lawyer to draw up this agreement if you are a large company that has a big enough budget to cover the costs, but this is not necessary as you can do it for yourself. You can of course write out your own agreement using one of the many different templates that are available for download online. Both of these documents are completely binding in a court of law, the difference is the amount of money you are going to have to spend. Each of them must be signed by both parties and in many states notarized in order for them to be legally binding.
If you have never filled out one of these agreements you will find that a joint venture agreement template can make the task much easier. The majority of these templates come with a full set of instructions to help make sure that you fill out your agreement in accordance with the legal requirements of the state you plan to launch your joint venture in.