I found this great program for renaming mp3's without having to do much at all. It's called "MP3 Rename" by No Design Software and is great for automatically renaming mp3 files based on a few rules that you specify. If you're like me and have a ton of mp3's that are improperly named, then this program is perfect for you.
The program itself is easy to use, especially if the music files have an ID3 tag. The UI is relatively simple and best of all it's free. MP3 Renamer can read and write ID3 v2 tags, preview files before renaming, move files into folders, etc. This renamer program is super small (300KB) and doesn't need to be installed making it excellent for use on an Ultra Mobile PC. Check it out!