You may want to consider using a freelancer website to handle projects for you. Visit:
http://www.scriptlance.com
http://www.elance.com
You can post jobs, and receive several bids on each project and then choose who you want to work with.
They keep your funds in escrow until both parties are satisfied with the work and once satisfied the funds are released and if dissatisfied the funds are returned to you.
All freelancers are also given a rating system helping you choose a good freelancer.