Exchange Server 2010, 55 users, 1 location.
Here are my thoughts
For resource mailboxes, they can be "zBoardroom", "zLaptop", "zProjector"
For distribution groups, they can be "yHR", "yOffice", "ySales", "yOperations"
In this way, they will show up at the very bottom on the address book so the users can easily locate them.
Does the above naming convention make sense to you? What is your way? I believe there must be some better ways than mine.