I use tfabris's tip on exposing the tracks as .wav's and use RazorLame to encode.

If you're starting with plain .WAV files rather than using an integrated ripper program, I don't know of any way to interface with the CDDB. One of the data points that the CDDB uses is the CD's serial number. A pile of .WAV files on the hard disk (or exposed in the filesystem via a special driver) won't have that serial number, hence no way to look up the files in the database.

The reason AudioCatalyst and its ilk can use CDDB is because they have the CD's serial number right there along with the track count and track lengths, and they can do the whole thing in one shot.

Personally, I don't mind typing in the track names. If I'm using LAME, I just run my "Jack" front-end to make it easy to type the names in.

___________
Tony Fabris