Maddog writes "The GIMP offers several methods for adding text to your graphics. You can use the "Add Text" tool or the more versatile "Dynamic Text".
Start by creating a new image. Add some color using the fill or gradient tool. When you've done this change the foreground color to the color you'll want to use for your text. Use something that will look good with the color(s) you've used to fill the background layer and will contrast with those colors enough to show up. Now select the big T ("Add text to the image") in the toolbox and left click inside your image. The "Text Tool" dialog box will open. Type a letter or word into the "Preview" area. Scroll down the font list and select the font you want to use. The previewed text will change to the font you've selected. You may have some choices displayed in the "Font Style" column depending on what options are available for the font you've selected. You can use the default "medium" or change to "bold" or "italic" if these choices are available. Again, your choice will change the previewed text. Now select a size for your font in the "Size" column. You'll probably want it to be fairly large for our purposes here so select 64 or 72 points if these sizes are available. When you've made your choices click OK and the text will be added to your graphic as a floating selection using your foreground color. If you're happy with that color anchor the floating selection by hitting the "New Layer" icon at the bottom right of the "Layers, Channels & Paths" dialog. Before you do this, however, you might want to experiment a bit while the text layer is still a floating selection. In the floating selection the borders of the text will appear as a selection. Make some changes to your foreground and background colors, select the gradient tool, and drag your mouse through the text. You can get a bit fancier with your color fill this way. Go ahead and anchor the floating selection when you're satisfied and the floater will become a "Text Layer" on a transparent background.