Here are some online resources to help you learn more about Adobe Photoshop.
The About.com site on Graphics Software has several articles about Adobe Photoshop, including tips, tutorials, book reviews, and information about plug-ins that give Photoshop additional features. (Note that much of this info is directed more at print designers than web designers.)
The tutorials at Elated.com are directed specifically at web designers. Take a look.
PEI Magazine offers tutorials (in PDF format) on how each of its magazine covers was created with Photoshop. Covers for 2001 and 2000 are available. (More recent tutorials are only available to PEI subscribers.)
Macworld magazine offered a history of Photoshop from its 1990 debut to the August 2000 release of version 6.0. You might find it interesting.
We practiced Photoshop 6. What about Photoshop 7? PC Magazine summarizes the new features in versions 7: a File Browser, new painting tools that simulate watercolor or charcoal, and better tools for repairing scratches and other damage on scanned images. The list goes on.
Photoshop is so successful that it has become a verb: The process of tweaking an image for publishing is often called photoshopping. That said, Photoshop does have one or two competitors worth mentioning. The principal contender is Macromedia Fireworks, from the people who brought you Flash and Dreamweaver. (For example, illustrator Grey Blackwell used Fireworks to help build his home site.) Coming in a distant third is Jasc Paint Shop Pro, cheap, reliable, but less spectacular than Photoshop and Fireworks.
Photoshop tennis, a game pitting two pro designers against each other, is a fun way to see what Photoshop is capable of. One player emails a new Photoshop document to the other, who adds a layer and “volleys” it back. Each volley is posted online with play-by-play comments. The site visitors vote for a winner. Please note: Some designers have a raunchy sense of, er, humor. I thought the 9.7 and 10.12 games were a waste of time, but the 10.19 and 10.26 matches are among the best. New games are always scheduled for a Friday; the most recent was on May 17.