Well I have over a years experience in GIMP, and have written a couple of guides on it. One is on youtube, then I do have this quick video of using the paths tool to create a piece from scratch. And finally I also have a guide on making a signature in GIMP.
Oh and shameless plug for my live Q&A session . Plus you can book 1 to 1 sessions with me on skype (quietisunus)