Sitepoint is currently providing the download of a free 278 page Photoshop ebook called "The Photoshop Anthology: 101 Web Design Tips, Tricks & Techniques" which is available for download. The download will be online for a limited time (unitl Friday, June 13th) so go get one if you’re interested.
The book adresses webdesigners who want to know about techniques and inspirations for their webdesign (e.g. how to make aqua buttons, seamless backgrounds, diagonal lines and so on). The book covers Photoshop basics (images, layers, vectors, transparency, text) and goes on with advanced techniques and specials like image effects, CSS rollovers, graphics optimization, creating animated GIFs and designing entire websites. So the book contains lots of useful examples, techniques, tips, and tricks that you can apply to your own designs.