For your first question there are several ways. The hardest and prabably most useful way is to make them. The method I like for this is to draw what you want on paper then scan it in and use the pen tool in photoshop (or similar program) and basically outline it. It is actually easier then it seems.

As for graphics programs, I would suggest getting a free trial of Photosop, or Fireworks, both available free at adobe.com