It varies from school to school. My school opened at between 8-8:30am, and literally everyone had there results by 9am. It was quite amazing considering its a bunch of teenagers who mostly haven't woken by that early for more than six weeks.
If they don't contact you via post/email etc. (mine didn't) check there website - I assume most schools have one unless really small. They will usually update it there, though don't assume anything.
When your actually there you pretty much pick them up in envelopes, and I think thats the standard. Don't worry about that, thats the easy part! It's trying to avoid teachers and the like from hounding over you as you open them thats difficult.
Then we had chats to confirm choices and get help etc. though again, it varies from school to school. Hope this helps!