Apart from checking out various freelance sites as suggested by CubicalPhil, you can also post your project to jobs forum here and other webmaster forums as well. Another way to find out about good web development and design teams is to visit the sites you like and are similar in scope to the site you want developed and then look at their footers, usually development companies put a link to their website their.

Before you hire anyone, make sure they understand the project requirements fully and are quoting the price for full project. Ask for a firm deadline by which they will deliver the project fully working. Ask if they'll provide support once the project is delivered and will they patch any bugs which are discovered soon after delivery. And don't forget to ask for sample of previous work and references.