What's the best way to set up a partnership?

I'm have been asked to enter into a partnership with an experienced investor, and I'm not sure how to or the best way to structure a partnership. Any advice or resources you can point to? I'd like to double my units in the next year and the best, more feasible way to do it is with someone that has done for over 40 years. I've done my projects solo so far and it has worked out for me, however, it is time consuming and not in the position to invest all into one deal. Partnership seems like a good idea. Any suggestions? Thanks!