Finding a great partner in business i much like finding a great partner in life. It takes time for both of you to know and understand each other. Rushing in because it's the thing to do is a recipe for disaster. Make sure you have the similar world view, values and vision for the future. Working on projects together is a great way to "date" - get to know a prospective business partner. I'd recommend it as part of the due diligence for anyone looking to form a legal partnership. As one entrepreneur shared with me "I've been through a divorce and a break up with a business partner. The divorce was easier".