Blender is the free open source 3D content creation suite, available for all major operating systems under the GNU General Public License.
This book is a great tutorial to the free, open source Blender 3D graphics modeling and rendering software.
The GNU Image Manipulation Program, for X Windows systems. Official site, including download area, documentation, FAQs, and a plugin registry.
Gimp-tutorials.net, New fresh tutorials everyday! learn how to apply effects,manipulation,icons,textures and much more tutorials. all for Gimp
Community with news, tutorials and infos about the GNU image manipulation program (GIMP)
An Open Source vector graphics editor, with capabilities similar to Illustrator, CorelDraw, or Xara X, using the W3C standard Scalable Vector Graphics (SVG) file format.