Love the old Hammond consoles, and when I got my hands on one I decided to log my experiences and the information I found on the web to this blog, I also play sax and bass, and sometimes take out a cigar box guitar for that instant ZZ-Top sound. I'm an active member of Wikiloops.com where you will find a fair few tracks I posted with these instruments.
Something else I’ve been experimenting with, with better and better results, is using the Rotor in Logic, based on suggestions from Jim at the Organ Forum. If you combine this with the overdrive, or one of the amp simulators (‘Moving Air’ is a good one) you can get very good results, and this works very well for recording, taking the signal directly from the line-out on my A-102; I’ve been struggling with how the Vent is sitting in the mix, and the levels I get from it. This may just be related to my own setup, but I’m pretty much using Overdrive / Amp modeller / Rotor now, sometimes using Spreader and Exciter for an even bigger sound, and either the standard bus 2 platinum reverb (add other buses with reflections to taste) or a modelled reverb room.
Don’t forget to set the record mode to Latch or Write to capture Leslie-switch events (I send my CU-1 through a foot switch input on my interface for slow / fast switching).
Here’s a Hammond B3 / C3 User Manual in PDF format. The manual applies to both the B3 and the C3 equally, since the only difference in these models is the different cabinet. Much of it will also apply to the A-100 series Hammonds, which also have a power- and a reverb amp, not found on the B3 or C3, but use the same tone generator, pre-amp and other components as these models.