It is probably best to just browse the articles here, although watch out that many of them are programming articles which probably go into things that don't interest you.
If a book is acceptable then the Dummies book will do what you are after.
Eric has copies for sale at a discount on the front page of this site:
http://www.mp2kmag.com/
Yes, the Dummies book refers to MapPoint 2002, but very little functionality has changed - ie. the book works almost as well with 2004.
The main changes between the two versions are updated roads, new or updated demographic data, bug fixes, and a couple of minor changes for programmers.
Richard