you should have a print out coupon to redeem for a coupon booklet if it is included.
If you don't have this, I'd frankly suggest just asking for one. They are only supposed to be given out to people with the required printout, but, if you are nice, you will likely be given one as there is no tracking of this and the GS coordinator won't get in trouble. But you BETTER BE NICE! Be prepared for a 'no' as that is only for guests who have done 'xxx' like getting a GE credit card or booked thru UO with a promo. But heck, it never hurts to ask!
Mostly it is 10% off most things... not a huge amount, but if you really do stay at UO it can add up.
The coupons are mostly good for Islands of Adventure, Universal Studios and Citiwalk (and the hotels restaurants). don't expect coupons for anything off-property.