I'd also recommend at least looking through job postings with similar keywords. To what you're looking for on oDesk.com and freelancer.com, to get an idea of what things you want to specify for the job itself, and to get an idea for the going rate for similar work… You may even find a contractor or three worth speaking with further, and be able to (at least on oDesk) get some pretty immediate feedback on how much experience they have via their test results, total hours/jobs worked, and portfolio, and whether or not other outsourcers are happy with their prior work via ratings and comments/feedback on actual jobs.
Deano’s answer to: “Where can i go to find a cheap wordpress developer?”
deano.com 