Hi there,
I'm no expert (just done a couple of pigs each year for a couple of years) but my experience has been: firstly you need to decide how you're going to get the butchering done. Some abattoirs have a butcher alongside, sometimes another local butcher will collect a carcass for you from the abattoir (so you just collect the meat yourself from the butcher). Friends of mine who have done the butchering themselves at home (keeping all of the meat for themselves) have indeed picked up the carcasses straight from the abattoir, and popped them into the back of their car.
Costs of all of this vary hugely it seems from county to county.... here in Devon we pay about £30 for a kill and then the butchering is often done by weight (so a 70 kg pig might cost 50p a kilo so you're paying out another £35 for the butchering) - but some TASers report much cheaper 'kill & cut' costs....
I'd suggest that you simply call the local abattoir and ask what they cost, and if you have no pals to recommend butchers, then ask the abattoir (recommendations for both abattoirs and butchers are invaluable!) for a recommendation, and then ask what they cost.
As for timing, again it varies. It wouldn't be unusual for you to be able to collect the carcass anytime from a few days to a week or so after the kill - so that the pig is hung in a properly chilled room for at least a short period...
Hope this helps a bit - no doubt you'll get more informed information from others here later....
Good luck - there really is absolutely NOTHING like eating your own well looked after, properly fed, and cared for pigs.....