First time Biasing tubes

In some of VTL models there's one extra bias pot which is called Master Bias that regulates the bias current on all of the tubes.
In some tube models designers would place an extra bias pot onto each PP pair of tubes to adjust them both and each one independedly.
The red color leads on your voltmeter should touch the bias slots and the black color lead should touch the ground or chassis. You may also connect the black color lead onto your ground binding post.

Thanks Marakanetz!!! - I think I get it now! There are two bias slots marked left and right and now that I think about it, the two pots I see may be actually be two bias pots - one for right and one for left. Does that sound right/possible? I was applying my voltmeter to both bias slots (duh!).

No it's NOT right!
Bias slots are ONLY for the RED lead of your voltmeter.
The black ground lead of your voltmeter should be connected to chassis or ground speaker binding post.
RIGHT and LEFT mards I assume are for master bias controlls for each CHANNEL to add more flexibility towards using unmatched tubes.
I'm not familiar with Scott amp and telling you from the general tube experience and knowlege of a major tube circuitries.
You should also know what bias level you should set according to manuals. You should use a milliVolt scale on your voltmeter if it's not digital with auto range.
Slowly vary the trim pots in order not to over or underbias too much.

Marakanetz - I actually understood you the first time, but did not make that clear. Two bias slots - connect red lead of meter to one, black lead to ground. Set bias. Repeat for other slot. Thanks!