To do this, as soon as the CD track info shows up in the iTunes window, click on one track, then quickly type Command-A (to select all) and then Command-I to open the get Info window for the whole CD. As long as this dialog is on the screen, iTunes won't start ripping. Make your changes and click OK to resume.
If some of the track info is also wrong, you can change it during the rip, as long as iTunes hasn't gotten to that track yet.

