If you played Ocarina of Time or Wind Waker, you already know the control scheme for Twilight Princess. The 'A' button controls talking, picking up items, throwing items and many other movements. 'B' is generally attack, and the joystick controls movement while the yellow joystick controls the camera. 'L' targets enemies and 'X' and 'Y' control extra items like the Clawshot or arrows. Even if you haven't played another GameCube Zelda title the controls are so intuitive you will easily figure it out within a few minutes.
One of the added features to Twilight Princess's gameplay is Link's ability to turn into a wolf. As a wolf, you can sense smells and ghosts of objects. Also, Wolf Link can dig and fight as well. Sometimes you even need to use Wolf Link to fight instead of human Link. This is probably one of the best parts of the game, although it does take some getting used to.
Another great feature of the gameplay are the added items to Link's inventory. There are two brand new items (a ball and chain and a spinner that Link rides on), some combination weapons (bomb+arrows=awesomeness!) and two (yeah, I said two) Clawshots (same as a Hookshot), and a boomerang that creates wind. There is also a lantern, which is a throwback to Link to the Past.
The set up of Twilight Princess is the same as other Zelda games too. There are a few towns, a large (and I mean large!) overworld map to explore either on foot (which would take way too long) or on your horse Epona. Also, there are nine dungeons Link must complete to fulfill his quest. Many of the dungeons follow the same themes as dungeons in past Zelda titles. There is a forest dungeon, a Death Mountain dungeon and a Water dungeon. However, there are also some nice new locations thrown in, including one that takes place in a crumbling mansion in the snow.
All in all, the gameplay is good old Zelda with enough new stuff to keep even the oldest fans interested.