The coupon books have a variety of deals. There are a lot of 'Bring a Friend Free' or 'Bring a Friend For $19.99'. They also have coupons for games, like buy one get one, or $1 off. Then there's the food ones. They have $5 off of family meal deals, buy one get one 50% off meal baskets, $1 off popcorn, etc. I think the only coupon you can use at other parks besides your home park is the 'Bring a Friend to Any Six Flags Park For $X.XX'. I'm not sure how much that one costs, or if they even had it this year. Hope this was kind of helpful.
And just as a basic FYI that I'm sure most of you know. If you buy 4 or more, and get them processed by the end of the 2012 season, you get a free upgrade to the Gold Pass. And they also normally have Season Pass Processing Days the week before the park opens. If you can't get it processed this season, get it done then. This past April Break the processing lines were reaching 1 1/2 hrs, and that's with both processing locations open (Hall of Justice and Regular Processing Building).