I have been using Photoshop for 9 years and found that it is impossible to learn everything since it keeps getting updated every year! I have a great source for those who need photoshop help! Go to
www.lynda.com, she has incredible books that are great for the beginner to learn from! Photoshop 6 and ImageReady 3.0 is her latest one. Her writing style is simple and easy to understand and there are lots of sample lessons to view. Her books have been a life saver for most of my students, and also for myself! Also very helpful for web portfolio help! If anyone ever has any questions about Photoshop, I would gladly help! Also, I use a CoolPix 990 for shooting my subject matter. It is a perfect marriage with Photoshop users!
Hope that helps!
