I first started with Photoshop, but ran into many challenges. The most frustrating was having to click on the layer I wanted to work on. I always forgot that piece, then I would mess up a different layer and need to back track a bit. Then I was turned onto Fireworks.
Compared to Photoshop, Fireworks is a dream. It is pretty easy to learn the tricks on this program and- no more going to the navigation bar of your piece to change layers!