We don't have any rocks so I can't help much with that, but I do have a couple of different tillers and have used them quite a bit. The main thing to keep in mind is that the tractor will Not be pulling the tiller, but rather the tiller will be pushing the tractor. So start out by traveling as slow as your tractor will allow until you get the feel, especially when breaking through turf since the tiller will have more traction than in previously tilled ground. When you get to the end of a row, either raise the tiller or just stop it from rotating or else you'll over-run your row. I pushed myself into a fence post last year by just clutching the tractor, thinking that would stop me like normal, but instead I shot forward since the tiller was still in the ground.
When breaking new ground I usually drop the tiller only three inches or so and then make another pass or two at full depth. On new ground there'll be a lot of weed seed turned, so it's a good idea to till it in the fall or at least early in the season and then till again after all the weed sprouts shoot up (before planting). For me, it usually takes two or three years to get ahead of the weed load. Look into drip-tape and plastic mulch if you have too much weed trouble.
The last thing to keep in mind which you probably already know is to avoid tilling if your ground is at all wet. After it dries the ground will be very hard and you'll have to till it again, and even worse you run the risk of destroying the natural tilth of the soil.