Start with writing a job description for your deal candidate, post on a few boards, and start looking at resumes and portfolios. I would advise not overloading it with irrelevant keywords. you dont necessarily need a designer experienced with java, php, python who can write you iphone and android apps while being able to answer how many marbles can fit in a school bus.
I would try posting your job description to design centric sites. there are a bunch out there. At least you can target your audience. Spend a little money on it if you have to.
Ive posted on CL and other free sites and i'll get back too many resumes with a bunch of overhyped nonsense buzzwords.
Have someone who knows design/ui help you look through portfolios. Ive scoured through hundreds of designer's sites and portfolios over time and i can see their trends, styles, methods. If they do dev, ask them what theyve actually developed, theming, js/jquery, etc.
Things to pay attention to:
- the person's education/background in design. if they're not designers by nature... would you hire them?
- Avoid an engineering centric person too. Engineers are typically not designers. (please dont get mad for that statement)
- take a detailed look at their portfolio. Do you like what you see? do they have a certain "look" that you like? or do their sites look sloppy, too much like some template, etc.
- if you care about ux, does their site provide good experience? is it at least usable, logical and consistent?
- Avoid flash designers. Most flash guys know little about seo. Content management will be difficult too.
I think you'll have a hard time finding a designer who can design, code and do seo. There are smaller web shops out there that can help. Make sure you know what you're buying into and ask for references.
One thing i warn you is to becareful with eye candy. There are a lot of tutorial mongers out there who will run through psdtuts, create some variation and add it to their portfolio.
i agree with andres, use a cms. im a fan of drupal.
k. hope that help.
-jay