GIMP

Well in my free time I have decided to learn how to use GIMP. For those of you that don't know, GIMP stands for GUI Image Manipulation Program. Basically it is an open source version of Photoshop.
Yesterday I started reading the online manual (which I should probably download to my computer sometime soon) and was somewhat insulted by the simplicity of the first few sections. However, I can see why they are needed. As of now most of what I know to do was discovered by playing around with the program and reading random portions of the manual.
Right now my goal is to be able to create a cool banner for the portion of this blog with the title. I already have a few done but none of them are "amazing" so they are not going to be used. I think the first thing I should find out is the necessary dimensions for the banner.
The program seems pretty straight forward so far, however, I would like to learn how to make manipulations to text.