From the Project team blog (this looks like a useful end-user Project guide):

"It can sometimes be a challenge for new users to find their way through Microsoft Project on their way to becoming project managers.  The Project team has just produced another Help product that will help you understand Microsoft Project-The Project Management Quick Reference Guide. This template can be downloaded and printed out for ease of use. Now you have another tool to help your organization achieve its project goals.

Note that the guide requires Word 2007.  The guide was written for Project 2007 but it has a lot of information in it that also applies to previous releases."