I also helped feed, clean (cubisan), water, lay down straw, (awful giant soggy bales which didn't unroll right!) place lambs and sheep in cubicles and trailers, dip the sheep, moor walk to chase the expecting ewes into a trailer, chase the escaping lambs, and the other stuff (which I didnt do) was to spray paint numbers and dock tails. It sounds busy but most of that gets done first thing in the morning and then we were all waiting for lambies to pop out, which always seemed to drag, then three would go off at once! Oh yeah, stopping random sheep from kidnapping lambs is hard work!
You definately want to get hands on experience of aiding a ewe, just ask after you've observed a couple of times. Also if you get an abnormal presentation which you're not comfortable with sorting out yourself, get someone ASAP as most turn out fine if your quick enough.