GIMP is not a "drawing program".
GIMP is a raster image editor. Of course you can use GIMP for drawing with too, although it wasn't actually designed for that. And neither was Adobe Photoshop.
If you want to make GIMP better for digital art, you can get the GIMP Paint Studio addon here for free: http://code.google.com/p/gps-gimp-paint-studio/ - its a collection of brushes and presets to make digital art easier in GIMP
If you find GIMP too hard, you can get simpler drawing applications such as MyPaint which is also Open Source and free http://www.mypaint.intilinux.com (works on macs, windows and linux computers).
If you use a Mac, Seashore is based on GIMP's technology - it's a simplified version of GIMP which runs natively on Macs http://seashore.sourceforge.net/The_Seashore_Project/About.html
Another open source and free program is Krita http://www.krita.org
If you are interested in vector image editing you can also get Inkscape http://www.inkscape.org
If you are interested in animation, there's also a few others Open Source applications that might interest you:
Synfig Studio (2D animation software) http://www.synfig.org/cms/
Pencil Animation (simple 2D animation software) http://www.pencil-animation.org/
Blender - complex 3D image modelling and animation http://www.blender.org