In iTunes, you can select multiple tracks, "get info", and edit them at once. If you want to do more tricky tagging, I know there are a ton of scripts for macs
here, but I'm not sure about scripting iTunes in a windows environment.
MusicBrainz definitely has its uses, as well. I had a dozen or so "mix" CDs that I made several years ago. I ripped them to mp3 and threw them at MusicBrainz, which identified a good portion of the tracks. I was very impressed.