Approached to enter partnership to expand painting business?

My hubby and I own a one man painting co. We were approached by a friend that wants to, in his words , buy into our company. We've owned the co. For 2 years and see this as an opportunity to expand and employ people out of work. I work full time and my husband spends time painting so it's hard to get work, and rely on word of mouth. So thus guy is proposing finding the work and bidding on the jobs, my hubby would do the work. My hubby would make his decided pay rate, materials would be paid. What remains after he wants to split 50%. As small business owners in a struggling economy, we are a little weary, at the same time it offers us a chance to grow and employ others. Any advice is welcomed!