I recommend this very cheap, very good book:
http://www.amazon.com/Teach-Yourself...7878619&sr=8-1
My mum just got it as she will be taking Photoshop Elements classes at the local community college (one of the cheap classes available for retirees
)... it is the required book for this class... I gave it a good look... lots of screenshots, very detailed, very good step by steps... well worth it!