I use Pixlr when I don't feel like opening up Photoshop/my memory's limited. It's very similar, but as nebari mentioned, a basic version. Not all the functions are available, so the standard steps people use in Photoshop tutorials many not necessarily translate directly. However, since it is so similar, there's a good chance they will.
I don't have any tutorials either but there are some floating around here for different icon effects that you might be able to duplicate in Pixlr.