Get Photoshop and spend time learning how to use the tools before you try to become an artist. Get your skill set down first.
While you are learning to use the application spend some time surfing the net and looking at the myriad of plugins available for special effects to get some ideas on what you can do with Photoshop.
Use something like SnagIt to grab images of web pages or parts of pics you think look attractive. Import these new pics into Photoshop as a layer and work on recreating a duplicate of the image on a new layer. Basically learn by tracing, then you can delete the SnagIt pic and modify the traced pic to improve it.
