I don't know which device you have, but the "Dummies" book series just published
this last month. It covers the WM2003 OS, but it is geared towards IPAQ's. If you are unsure if it will help you, the Table of Contents is available on the website.
I have numerous advanced technology books but I will also admit that the Dummies series has it's merits as well. They take a humourous and fun approach and can be very infomative.
Good luck!
KCT