You didn't say which version of MS Project you were handed, but the best book out there (IMHO) for any version is published by QUE... written by Tim Pyron and is titled "Special Edition Using Microsoft Project 2000" (or 98, or 2002 pick the version). It's a big book... over 1000 pages... but worth every penny!
There is also a tutorial within the product, it is only introductory but should get you started. If you have never used a Project Management tool and/or are not a project manager familiar with defining tasks, resources, resource allocation, creating a work breakdown structure, etc... then you need a project management course...
Hope this helps!