To be honest, there's no real substitution for traditional media. I do do most of my artwork on computer, but I spend an awful lot of time just doodling in my sketchpad, and without skills learnt from normal pencil and paper drawing, I'd be pretty useless digitally.
By all means, give digital painting a shot, but don't disregard traditional. Sketchpads and pencils are cheap, and more portable than even a laptop. Dabble in both and see what you prefer and get best results with