GIMP originally stood for General Image Manipulation Program. Its creators, Spencer Kimball and Petter Mattis, initially started GIMP as a semester-long project for a class at the University of California, Berkeley. Both were integral members of eXperimental Computing Facility, a student club at Berkeley (the GIMP's file extension, XCF, is taken from the initials of this club). In 1997, after both Kimball and Mattis had graduated from Berkeley, the name was changed to GNU Image Manipulation Program when it became an official part of the GNU project.
GIMP can be used to process digital graphics and photographs. Typical uses include creating graphics and logos, resizing and cropping photos, changing colors, combining images using a layer paradigm, removing unwanted image features, and converting between different image formats. GIMP can also be used to create animated images using an improved layers method. The full capabilities of the GIMP extend much further, however, and include advanced image editing, manipulation, and professional graphics creation.
GIMP is also notable to some as the first major free software end-user application. Previous free software projects, such as GCC and the Linux kernel, were mainly tools created by programmers for programmers. GIMP is considered by some to be proof that the free software development process can create things non-geeks can use productively, and as such psychologically paved the way for such efforts as KDE, GNOME, Mozilla Firefox, OpenOffice.org, and various other applications that followed.
Try this link: http://www.gimp.org/tutorials/