This gimp video tutorial touches base on a very powerful tool that if used properly can really improve on your photo editing. Layer modes allow you to dynamically change how your image appears by modifying how the layers underneath look.
This Gimp Video Tutorial talks about a very cool discovery I recently made while writing my upcoming book on layer masks. I was digging through Gimp's documentation, and discovered exactly how Gimp looks at colors to determine how light or dark parts of any image is when you desaturate it.
This video talks about how you can take what I learned and apply it to your layer masking using gimp.
In my Gimp Tutorials, I frequently use Wacom Tablets. Here is an awesome wacom tablet I recommend using.
A Wacom tablet will enhance your GIMP photo editing experience by offering a pressure-sensitive touch that translates to varying transparency when making brush strokes in GIMP.
Gimp Reference Manual
I highly recommend getting this Gimp book to use as a reference manual in conjunction with my tutorials. This book will explain how the tools I use work. My tutorials will give you practical applications for the tools shown in this book.