go to odesk or elance to hire a wordpress developer
look for someone with
excellent html5, css3, javascript skills
knows wordpress api very well
knows on page seo markup well
can take photoshop files and stitch them together
make sure that you also got a good photoshop designer who has created the look and feel of the site before hiring the wp developer
lastly, make sure the wp developer has done previous work
ask him or her to show you their portfolio
if it looks amateurish, look elsewhere. most will be crap.
when you receive the package, make sure you test it out with dummy data and run it through a html and css validator. make the developer clean his shit up before you pay them.