MP3 ID tag Editor

Hello

I am pretty new to ID tags for MP3's back in the day I used to strip all tags because it didn't matter on my previous MP3 players, but now that I am making play lists and such, and am Merging the wifes MP3 collection with mine, I am in need of 2 items, a ID tag editor ideally one that can do multiple MP3's at once since I have many albums, and 2, a MASS MP3 renamer, because the wife has NO rhyme nor reason to the names of her MP3's lack of formatting drives me insane

any help would be great.
I am downloading
"MP3TAG" and will try it now

Many library software also have sufficient retagging abilities.

MP3Tag isn't bad. The Godfather is another free alternative.

IMO the best tagging program I've used is Tag&Rename (not free, but worth it for the excellent list of features and decent UI).