Hiya, I'm new to this forum but I've been doing digital art for a while. You don't need anymore than you already have to start. A wacom tablet enable you to have the same kind control you would have with a pen or brush. Meaning you can paint and draw digitally. But you definatley dont need one to start. I would say familiarize yourself with the programmes painter or photoshop, and experiment. at the end of the day you need to understand the tools then the rest is up to your imagination.
Its all fun and games until someone loses an eye!