Start with the free things. Learn GIMP instead of PhotoShop. There is a free graphics tutorial at freewebsitedesigntutorial dot com/l2 dot php. It will get you started with GIMP and a few other free graphic programs.
Just start to read some photoshop tutorial in the internet and try to practice everyday. And you will be good in creating design.
I wanted to learn as you did, and all i've done is watch endless tutorials on youtube and joined Forums, Read Blogs and so on and im learning stuff bit by bit
Learing basic tutorials from photoshop and fireworks help.doc, then view youtube video, follow them to do step by step