You simply need to go on crème de la crème and click on "Find the best freelancers". From then, you will have to describe your need in details to get proposals that match your mission. The more details there will be, the easier it will be. Freelancers will then be able to create a scope statement as well as a quantified quote.
All of your activity and contacts will be on your personal crème de la crème account from which you can talk with freelancers, follow your missions and find all of your invoices.
For any other question, you are more than welcome to contact the crème de la crèmeteam through the chat (bottom right part of your screen), Twitter, Facebook, and Linkedin.