A local shop says theyll break in my flat tappet 440 for about $300, more if I want to spend time playing with different components.

Ive never seen or been around a real dyno. I have no idea how one should be operated. I dont know if there are 'good' or 'bad' dynos. Is it easy to operate one incorrectly? Besides HP/tq curve and a/f ratio, what other info should a dyno give you? The shop is great, but im kinda nervous, I dont think they've had the dyno long. Is there anything I should watch out for?