Hey Scott, I've got more than 3,000 hours on a IIB. Maybe 100 hours on IIBa.
Boy, where to start. They are really simple units but they can really provide you with a lot of info. Don't be afraid to turn the transmit power down if need be. You're not losing a lot of depth when you do.
With the dual mode (ie: two tones), you can turn disc way down to around 8-10 unless you're hunting a park for coins. Aluminum pull tabs won't get tuned out until you're around 53 on disc. But if you're in a campsite or battlefield -- 8 to 10.
If you've got prior knowledge that relics are in your particular site are really deep -- go slower than a typical sweep of 1ft=1sec.
Tones: when you get a faint "nail" tone that sounds like a nail somewhere around the 12-14 inch inch range, scrap the ground with your boot. Crisscross the coil over the target. In other words, "try" to make the signal good. If it clicks or sounds off with a high tone at all -- dig it.
There's more to it but this should get you started. The Bas are super relic machines. Both the B abd the Ba have their place but I think you'll like that DMC.
Hope this helps, Scott
Richard