Hi, enjoyed the course, some great basic information but will you ever produce an equivalent course using GIMP?. I will never be able to afford photoshop so I need to learn how to be proficient with GIMP instead.
I work to try and make the tutorials non-software specific so even though I'm teaching in Photoshop, all the lessons and material can be applied to any software. I work with basic brushes and rarely use filters or Photoshop only tools to make sure artists working in any software can feel like the education can still apply to them!
Having used both GIMP and Photoshop, there's really not much of a need for a separate set of tutorials for GIMP. Many of the features in Photoshop are in GIMP as well, though you might have to look up how to use the GIMP equivalent is.
That said, you can get Photoshop for the same amount per month as a CGCookie subscription or half that if you spring for the photographer's package (which includes Lightbox.) This is one of the really nice things about the Creative Cloud subscription. It allows you to get those tools without shelling out hundreds of dollars up front. That said, you will be locked into paying that for a year, and canceling the plan is a pain in the butt (speaking from personal experience.) If you don't like the idea of paying per month, Autodesk has Sketchbook Pro which will run $75-$100. Be warned that it is meant specifically as a digital drawing/painting app, much like Corel Painter, and the interface is much, much different. It does allow for custom brushes, layers, and layer blending modes, but it doesn't have anything like the Liquefy tool that I'm aware of.
Another App you may want to look into is Krita, which is open source and free. I've only been dabbling in that one, but it looks good and might be a worthwhile alternative to GIMP, though it seems Krita's brush engine is a lot different from GIMP's and Photoshop's.
I hope this helps you and anyone else wondering about getting Photoshop. I feel that it's a worthwhile investment, but I know that several people are not happy with Adobe switching to a subscription only model. The main reason I stopped my subscription was due to financial reasons that are not as pressing now, and I am think about going for the photography option this time instead of the whole shebang (mainly because it's cheaper than just getting Photoshop.) I think the model works well, even if it's a monthly or annual expense rather than a one time cost.
Anyway, sorry for going off on a tangent. I hope this helps you, or at least doesn't muddy the waters more.