Once you've chosen your design firm, plan a Kick Off Meeting. Invite all members of the project team.

This is an important opportunity for the designers to meet internal staffers who will be working with them on various phases of the project. It's also a terrific chance for the designers to ask many questions to elicit information on a broad range of subjects, such as: sites you like, sites you don't like - and why; any requirements from a creative perspective should also be discussed here, such as any font or palette requirements to conform to established guidelines, etc.

At the end of this meeting, the designer should have a clear understanding of what you want to accomplish visually and functionally with your site.

Other housekeeping responsibilities should also be set during this meeting, such as specific contacts for particular phases of the project, who will keep the meeting notes, how will information be shared back with the group, what will the timing of the review cycles be, etc.