How to handle multiple partners

[Robert Conlin]

How are everyone structuring multiple partners for RE deals?  Say 1 has good dti and credit so qualifies for the loan, another finances the down payment, another is a craftsman and provides sweat equity, etc.  Is a contract drawn up by a lawyer sufficient or do we need to get into a corp/llc (i believe this pushes into commercial loan then no?), etc.  Is there a BP podcast on this subject or something maybe?