What's the easiest way to do one of these, I'm a bit of a n00b, and keep in mind, I don't have photoshop.
1. Write down the 25 albums that you want to use.
2. Download GIMP.
3. Find the first cover, preferrably in large sizes (1000x1000 does the trick quite nicely).
4. Copy it into Paint, where you select a square area of the cover. The size of the square can be as big as you want, but it shouldn't be under 100x100.
5. Open GIMP, create a new 500x500 pic.
6. Copy the first cover segment into it and scale it so that it is 100x100. Put it into the top left corner.
7. Repeat for the other 24 covers.
8. Congratulations! You have completed your very own album cover collage!