When you launch GIMP for the first time, you will see a special dialog box. This allows you to setup GIMP to your personal settings, without affecting the way GIMP runs for other users. The first thing you'll see is the license to the GIMP — the GNU General Public License. Click continue if you accept the license.
GIMP now needs to create a directory to hold your personal settings. Under UNIX, Linux, and UNIX-like systems, the directory will be ~/.gimp-1.2, the tilde (~) means "your home directory" — often /home/username. Under Microsoft Windows the directory location will vary. All the files and directories which will be created are listed on the left-hand side. Click on any of the entries to see what it is for. If you want these files and directories to be created, click Continue. GIMP will give you a list of what was done. You should check this list for any errors and if everything is OK, click Continue again.
To make GIMP perform as well as possible, you can adjust several settings. For storing data about images which are being edited, GIMP uses a section of memory called the "Tile Cache". A good way to decide on a good size for your Tile Cache is to use two-thirds of the RAM available in your system. For example, 32MB would be a good size if your system has 48MB RAM.
Some images are just too big to fit into this cache, and so GIMP can use your hard disk as a type of additional memory. You should set your swap directory to an area on your hard disk which has enough free space — around 200