On the very first page of your site (the homepage) the first paragraph should answer the "5 W's"; basically telling them who you are and what you're offering. You'd be amazed at the number of websites that leave this out; making me think "what do these people do, and what's in it for me?" You need to answer these questions and do it fast. Surfers are a very impatient group. Stop them before they click away.
Welcome to our spaceship. just sit back and relax.