Well there is lots to see if you are a first time visitor, we have the barrier reef which you can visit from further up the coast. Fraser Island is accessible from Hervey Bay The sunshine coast and the Gold Coast if you like that sort of thing. There are a lot of Rain Forest areas quite close to Brisbane Mt. Tamborine, O'Reilly's Rainforest is accessed from the small town of Canungra only 60 km South of Brisbane, lots to see up there that is a must see the mountain parrots land on your head and shoulders to eat the seeds and nuts they sell at the shop at the top of the mountain. Are you going to hire a car or bike? Some very scenic routes you can take to places like Kyogle via Lyons Road - don't forget we drive/ride on the other side of the road here - it takes some getting used to, so take care, some folks from the US have had bad accidents trying to make the change.
I can pm you a lot of links if you are keen.