If today will be your first time at the Faire, Daniel Whitcomb has a few neat little guides of you to take a look at, right here on WoW Insider. First, we have a guide for those interested the Faire's ticket system(why you would be, I do not know), and another about the very cool trinkets you can get via the Darkmoon Decks.
The real awesome part about the Faire, though? The Iced Berry Slush. I'm serious! Go try one! Go go go!