Hi there, I bought a book for Photoshop from Scott kelby called The Photoshop CS book for digtal photographers. It is amazing and I have gone from beginner to being able to fix all sorts of problems. The thing I like is that it is not a Photoshop Text Book, but specifically aimed at US. I like that! And he has a good sense of humour and you can take what you want from each section.
Suggest you grab a copy. Its not going to cover all things digital photography wise, but I can HIGHLY recommend it. He has a web site and you can get it quite easily off the 'Net.
Kelby is a recoginized expert with Photoshop and his book for Digital Photographers is great. If you are looking for more information on PS you might check out www.photoshopvideos.com. They have some excellent training videos. Of course there is always the National Association of Photoshop Professionals (NAPP) www.photoshopuser.com. Membership is $99 per year and you can get nice discounts on Kelbys books and Videos (Kelby is President of NAPP). They also publish a great bi-monthly magazine. I am an amature and find the discounts and the magazine worth every penny of my membership.
At the end of the first paragraph is a telling sentence: "As well, many of the industry’s top manufacturers such as Intel, Nikon, Epson and others use The 123di Interactive Learning Suite for internal training. High praise indeed."