Just been secured my place on an architecture course today, after getting an A* A B, but when applying bear in mind that the highly competitive nature of architecture will dramatically affect you, where most courses in english or history or something would accept you if you got say ABB at A.S architecture seem to want you to of got the required grades more or less at AS, for example i wanted to go to oxford brookes which was AAB i think and i got ABB at A.S but lost out on a place.
I would also start the portfolio early, dont leave it right until your do your jan exams when most unis ask for them, spend a long time ad get around 10-20 hand drawings, paintings, model etc. that you have done and you will have a heads up