Hi,
Books from Step by Step series by Microsoft Publisher are pretty easy to understand and follow. You can try the following based on your need:

1. The 2007 Microsoft Office System Step by Step

2.Microsoft® Office Word 2007 Step by Step (Step By Step (Microsoft))

3.Microsoft® Office Excel® 2007 Step by Step (Step By Step (Microsoft))

4.Microsoft® Office PowerPoint® 2007 Step by Step (Step By Step (Microsoft))

Good luck