Edited title for n00bs like Ryan :P. Mark, I think you meant the 21st not the 14th? Doesn't start until the 20th!
Yup it's one of the largest fairs in the UK Ryan, a damn good one too. cod and I went last year, and although it was muddy as hell (see below pic!) it was fantastic to have so many rides in one place. Highlights of last year included some poor Scottish girl puking on Eclipse and Bomber Mk2 (which is a HUGE booster!).
I'll probably head up to Newcastle for the full day, do a bit of wandering, few drinks then head up to the Town Moor (it's a short walk from the centre).
Should be a good day, just hope the weather holds out :)