I'm assuming you're asking about Halloween Horror Nights? It's great fun! The parks close early so they can transform the areas into the scare zones, haunted houses, etc. DON'T MISS IT! They have information about this year's HHN on their website. Check it out!
BTW..if you have small children, I would strongly recommend not bringing them with you. It's not like MNSSHP at WDW.
The best tip is to buy our ticket in advance, and be in the park before the event starts. That way you can head to the stay and scream area, which is between USF and IOA. They let you go thru 2 mazes as they clear out the parks. That gives you a head start on the crowd.