With the powerful convert tools you can perform operations that are tideous to do by hand, just with a single click. It makes it a lot easier to give the MP3's correct names and a correct content of their ID3 tags.

If you have never tried the program before, there are tutorials that will quickly get you started. Also features a comprehensive help file covering every part of the program.

JJ MP3 Renamer is freeware - free to use, free to spread. You can download it here.
  
Works with Windows 98/Me/2000/XP.

Below are some screenshots of some of JJ MP3 Renamer's different parts. Click a picture to view it in full size.

Main window .	Advanced ID3 tag v2 options .
Full ID3 tag v2 support .	.Lots of convert tools

• Automatic modify tons of MP3 files in one click.
• Full ID3 tag v1.0/1.1/2.x support.
• Full support for m3u and pls MP3 playlist formats.
• Possible to work with ID3 tag v1/ID3 tag v2 separately (or combined) in every aspect of the program.
• Choose exactly what ID3 fields to write to the MP3 files.
• Convert tool: File name to ID3 tag reads the file name and uses it as ID3 tag.
• Convert tool: ID3 tag to file name uses the ID3 tag to rename the file name.
• Convert tool: CD database to ID3 tag lets you download ID3 tag
  information from the Allmusic.com CD database.
• Convert tool: Copy ID3 tag v1 to ID3 tag v2 copies fields from ID3 tag v1 to v2 and vice versa.
• Convert tools for adjusting the case of the ID3 tag text, cleaning out multiple letters (such as multiple spaces between words) and for replacing words or letters with userdefined text.
• Convert tool: Make playlist for Minidisc transfer makes it easy to copy MP3 files from the computer to your minidisc recorder.