The getting married part is pretty easy here, but I would not recommend applying for a visa to go to the UK as soon as you’re hitched. Regardless of the detailed procedure that very act sends out the wrong signals to the UK authorities if you do it too soon. These days our UK authorities don’t want new faces to come back I’m afraid, unless they can show absolutely that it is a genuine bona fide marriage.
If you want more detailed information on how to prepare for the Chinese formalities send me a pm and I can help. I’m the British Consular Warden for Chengdu so I can pass on any specific questions on details directly – like posting the bans for 30 days.
As others have said there is nothing wonderful about going to the marriage office here. It takes about 15 minutes (after queuing), and if you pay a little extra you get photos on your marriage book that you can actually see. Total cost less than 100RMB for that visit itself. The following wedding party location is your own choice, pick a hotel or a restaurant or other venue that you like and negotiate a deal, but your new wife should be able to help with that.
Too much stuff to write it all down here – as I say if you want more info send me a pm.
Thanks.