Start the Gimp by selecting "Gimp 2" from the "Programs" list
in the Start menu. When the Gimp starts up, it presents you with a "tip
of the day." Read this if you want to, and then close the window:

When the Gimp starts up, there are two windows open. One of these
is a toolbar that contains icons for a number of tools used in working
with images, tools for selecting colors, and also a group of options
for the currently selected tool. The other window contains different
panes for working with layers, channels, and paths at the top, and
panes for working with brushes, patterns, and gradients at the bottom.
Here is the toolbar window and the layers, channels, and paths window:

Here is the brush, pattern, and gradient selection area:
