Rain Harbour Resources offer free goodies like Photoshop and Gimp
Brushes + Brush Tutorials
Grunge
PS 7.0+: 17 | GIMP: 17 | Image Packs: 17
Miscellanous
PS 7.0+: 37 | GIMP: 36 | Image Packs: 36
Nature
PS 7.0+: 26 | GIMP: 25 | Image Packs: 25
Paint
PS 7.0+: 18 | GIMP: 18 | Image Packs: 18
Shapes & Structures
PS 7.0+: 33 | GIMP: 33 | Image Packs: 33
Textures Icon Size - 485 Icon Textures , 100x100 | PNG
Textures Paper Scans - 14
Textures Various Sizes - 77