Inside your USER folder is a gimp-2.6 folder.
Inside that gimp-2.6 folder are sub folders.
For instance in Windows it looks like this
C:\Documents and Settings\MyNameHere\.gimp-2.6\SUB DIRECTORIES FOR RESOURCES
NEVER EVER add anything to Gimps PROGRAM directory tree!
ALWAYS add new downloaded resources such as scripts (SCM files), gradients, patterns,brushes, and plug-ins to the USER directory gimp-2.6/ sub folders.
Each folder is named accordingly as to what goes into it.
ie... Scripts = SCM files ONLY
Plug-ins = Python, exe, and dll files
Brushes = GBR,GIH, and ABR files
Patterns = GIF, PNG, PAT, JPEG,JPG files (some pat files (ADOBE) won't work, and some will with the load pat plugin)
Gradients = GGR files and SVG gradient files created in Inkscape
And the list goes on.
Hope that helps you.