The second step is to clearly communicate what you want to the freelancer.
If you don't have a clear idea of what you want, the freelancer isn't going to know either.
No matter how good the freelancer is, you won't be satisfied with anything he produces. You might as well blindfold him, hand him some darts, and tell him to hit the bull's-eye.
You want a freelancer who is willing to ask questions. A good freelancer will want to understand where you're coming from and what you hope to accomplish.
If you want him to help you promote a product, he needs to know as much as possible about it.
Who is your audience?
Who are you trying to sell to?
What do you want people to do after they read your communications piece?
Why should people buy your product?
Why should people be interested in your company?
If you can answer these questions and communicate what you want to the freelancer, you're well on your way to getting results you'll be happy with.