What to look for in a Business Partner?

Hey everyone, I'm a Realtor here in Nashville, TN and got my license for the purpose of investing.  After listening to the past few podcasts, crunching the finances, and getting the wife's approval, I feel like I'm ready to take action on buying a rental property.  With that in mind, I would like to partner with someone and I've heard so many different things to value.

I think it goes without saying that Trust is important, but what else should I value highly?  Someone to fill in what I'm lacking? A mentor to guide the way?  Someone willing to help financially? Maybe just passion?  Does distance matter?

Any help?