We have been using
gmail enterprise email system for about 6 months and I have to tell you it is a great system. Like most of what Google is known for, biz
gmail is intuitive yet robust enough to handle a relatively heavy email user (I get about 150 emails a day). If you are looking for any easy to launch, low cost and full featured email system I think you'll find
gmail for biz a good choice. Here's a place to start
google biz email.
We have about 17 users on the system and although the email works great the google docs system has a way to go. We still have trouble with document conversions and I can't recommend google docs for any serious document management uses.
If you decide to try it let me know what you think.