Don't panic Tanith
......There are some horrors stories out there about kitten deaths and queens not surviving labour, Just take on board as much info as you can just in case the worst happens then it can be dealt with in a swift and timely manner.
Most books and articles on cat breeding will put a figure of 1 in every 10 kittens will not make it.....so you may think thats bad, but really its just natures way and will happen to you at some stage!
If you do everything right and have everything prepared then kittening will go nice and smoothly.....in most cases your only there to spectate, However the crucial thing is knowing when to act should something go wrong!
As rajique said - the health of the stud and of the queen is everything and provided both are in peak condition and free from any illnesses you shouldn't have any problems......some breeders will even give anti-biotics to the queen before mating and about a week before kittening time just to be on the safe side.
Anyways when the time comes don't feel you have to worry alone.....we'll all be here and the vet is only a phone call away!
You can also find our number and call it anytime night or day if you get worried.....we're happy to offer support to others, even in the wee small hours we will answer the phone.....theres always someone awake on kitten-watch duty in our house!
Lukey