I'm sure you'll get good advice from Silverback. I'm still getting the hang of it, but my thoughts as a newcomer are :
Find out where the rabbits are on your shoot. The landowner will probably be able to give you some good pointers here and save you a bit of time. Then find out when they're most active. The rabbits on Spam's permission are mainly round three main warrens, and you're most likely to see them in the last hour of daylight, particularly on overcast days or in light dizzle.
Equally important is to find out where the public are on your shoot, and treat them with the greatest respect. I prefer to remain unseen if possible. The last thing I want is the landowner (or the police) getting an earful about blokes with g*ns from Joe Punter, even if I'm entitled to be there. And know the law, would be my strong recommendation.
My view is that rabbits don't use their eyes the way we do. That is, they react to movement, but I've stood (still) in plain sight on watched rabbits many times and have been pretty well ignored. Make a sudden move though and watch them run. If you do move to position yourself for a shot, use whatever natural cover there is or, if in the open, move dead slow. You can make some surprising changes to position if you do it very slowly.
Rabbits have got great (big!) ears and a fantastic sense of smell though. Walk carefully, avoid twigs that would snap or leaves that would rustle. Remember that you'll be within their earshot long before you see them, so keep talking to a minimum and tread softly, as I think they can sense your footsteps through the ground too. Try to keep your hunting gear and clothes free of non-natural smells. If your kit smells of this morning's fry-up to you, it's going to be like a stinky siren going off to a rabbit! Equally, you don't want it to smell of fabric conditioner either (or woodsmoke, I would have thought). I keep mine in the garage away from smells, and I don't wash it much!
As for field kit, remember to take a bag to put the shot rabbits in, lined with a binliner or similar to stop it getting covered in claret. A pair of disposable latex gloves makes a big difference to the skinning and gutting process. A small sharp knife and a small torch are essential too, in my book.
And headshots, always headshots.
Hope that helps.
Rat