Tim,
Make sure the volume knob on the back of the amp is turned up all the way. Then put your master volume past 12:00 and your other volume at about the same. Put the gain about 12:00 also for a starting point. If its too loud just turn down the master volume. You should get good sounds from the amp on any of the clean models at those volume ranges. All your clean amp models are going to be on the lower end of the rotary switch. Your AC30TB might break up more so than the others at a higher gain setting but thats normal (so will the tweed 4x10). For now you just want to make sure your volumes are up enough to hear them. Once you get the feel of how each model sounds you can mess with the gain on each one. Remember to try pressing the Manual button first to tweak the models manually. The factory presets are usually set to low volumes.
You might also want to put all your tone settings right up the middle as a start. I'm pretty much set on 1:00 for treble, mids and bass on almost ALL my models now. Once you get the hang of how the volumes and gain work...your tone will always be "there". Good luck.
Guitars/Bass - MIM Fender Classic 50s Strat, MIM Fender Standard Strat, Squier Classic Vibe 50s Tele, Gibson Les Paul Studio, Epi '56 Gold Top Les Paul, Martin DSR acoustic, Sigma Martin Auditorium electric/acoustic, Squier Jazz Bass.
Amps/Cabinets/Modelers - Model 2558 50 watt Marshall Silver Anniversary Jubilee combo w/ Celestion Vintage 30s, 4x12 Marshall cabinet w/25 watt Greenback Celestions, Fender Blues Junior w/ a couple of Billm mods, Line 6 POD 2.0, Roland Micro Cube
Pedals/Effects - Cry Baby Classic Wah, Boss TU-2, Boss NS-2, Boss RC-2 Loop Station, Ross Compressor, MXR Micro Amp, Danelectro FAB Echo, Danelectro FAB Chorus, Danelectro Chicken Salad, Marshall Guv'nor Plus, Marshall Echohead, Duhvoodooman's Zonkin' Yellow Screamer, Digitech Digiverb, Digitech Bad Monkey, Dunlop Fuzz Face, Homemade Loop Bypass pedal, Duhvoodooman's Sonic Tonic (Maxon SD-9 clone +), Voodoo Labs Superfuzz