I took an Adobe Photoshop class that lasted about 4 hours. The first 2 hours the teacher showed us some techniques on how to use the product. The last 2 hours I spent making these pictures below. It's amazing what you can do in 4 hours from ground zero. Feel free to use these pictures any way you choose (webpage, wallpaper, whatever). Please let me know how you use it. Thanks.
Here is a spot to get great looking posters that might help you learn the guitar: