recording level ?

Gary,

IIRC you are using an M-audio as your input ADC, I would not be using the input control on that to control levels in.

I would do all the level setting in the analogue domain prior to the ADC input.

Aim for around -18dBFS average signal on the M-audio control panel level meter with the sliders set to 0.

Not being familiar with the circuit of your mixer I am not sure whether it is better to leave the master full up and control levels with the preamp gain, but it most probably is, this should leave your preamp stage doing the least work/signal distortion.

I suggest that you read, absorb and apply the information in the following article - http://www.massivemastering.com/blog/index_files/Proper_Audio_Recording_Levels.php he is not referring specifically to LP transfer, but the principles are the same.

Another reference with some handy extra info http://dbzeebee.blogspot.com.au/2009/10/digital-recording-levels-rule-of-thumb.html

Browsing the Audacity Wiki I came across the following link http://minorshill.co.uk/pc2/meters.html some rather interesting looking standalone software level meters that might be handy for initial level setting prior to commiting to recording.  From reading his descriptions they seem to have been engineered with serious intent to provide accuracy rather than being just a pretty gimmick.  Most are freeware, though the one I liked the look of (naturally) is not.  Will probably give them a try at some later time.