Photoshop CS/CS4 Differences

[dmerger]

I upgraded from Photoshop CS to CS4.  I would appreciate recommendations for a web site or book that describes in some detail the cumulative changes.

[sniper]

There were quite a few changes between those two versions, most books tend to go up one version at a time, best bet is just look for a good CS4 book, I have my doubts theres anything specific to your needs (I wait to be proved wrong)  Books by Martin Evening and Scott Kelby are pretty popular choices (I'd choose marting Evening) and work your way through the features .

[dmerger]

Thanks for the advice.  I just purchased "Adobe Photoshop CS4 for Photographers: A Professional Image Editor's Guide to the Creative use of Photoshop for the Macintosh and PC" by Martin Evening.