raulph go to this site
http://www.designsbymark.com and buy all 3 of his CD/DVD's they are on clearance right now.
The Photoshop Tool Kit will teach you all the ins and outs of PS and some tricks...the other 2 will teach you some graphics tricks and how to work with photographs.
Now set up a laptop next to your main machine and watch the videos while you actually follow along with PS...now after that's all done if you feel like you still need to take a class then go for it but I highly doubt you will.