I recently purchased Dr. Feickert's Adjust+ software to calibrate my turntable, and I just wanted to post that I think this is one of those must haves in your toolbox, if you're wanting to get serious about calibrating your turntable.
I know that you can use a multimeter to adjust the azimuth, but doing it this way doesn't allow you to see how your VTA interacts with changes in azimuth. This software reveals this interaction, and allows you to make sure that both your VTA and azimuth are calibrated correctly.
-Clayton