That’s why Apple calls it a “Library” in iTunes.
Once you get them all tagged right, that’s what it’ll feel like too—a real library of music and not just a big list of files.
On the Mac I totally recommend Clutter for adding in the artwork as well, that was my last big tag project, and now 95% of my 28GB of music has correct album art. Use an iTunes plugin like Jewelcase and it’s totally worth it.
I’ve also used the Composer field (which I don’t use and is too granular for my kind of usage of pop/rock/electronic) to store record label data, so I can add some smart lists in and shuffle out all my Ninja Tune or Stones Throw albums, for example.
Metadata is valuable!