Maybe Photoshop CS3 would be better, but I don't know as I've only got the Gimp... Hope you'll learn vectoring very fast, because I like Harribel's scan on your wally =)

Here are some basic vectoring tutorials:

- Vectoring PART 1
- Vectoring PART 2
- Vectoring PART 3

Hope this helps. ^^ Good luck on your Bleach wall.