I've seen various resources and websites about Gimp and with Gimp Tutorials. In my search for information on Gimp, especially as it applies to digital photography, I came across
this book. I haven't purchased it yet, but I would like to.
There are Gimp tutorials scattered all over the place.
Here are a couple of sites that I have used in the past for tutorials:
I have seen many tutorials that were translated from Photoshop to Gimp. You'll probably see some of that in those sites as well.
The
Gimp Documentation is a good place to look as well. Search Flickr groups for Gimp. You'll find several.
Though not totally Gimp-centered, this
blog focuses on Linux photography. I have found the information to be rather useful.
Joel has a
links page to software and topics that he's mentioned in his blog.
Try searching for "gimp photography"
here. If you don't find what you're looking for, at least you'll have fun doing it!