We were there in August and we watched from the Sleepy Hollow refreshment stand in Liberty Square- it's just after you cross the bridge and there's a seating area that justs into the river. As the parade crosses the bridge, you get an unobstructed view (except for the bridge railings). The nice thing is you can sit while you wait, and it's not too crowded. For the Fireworks, we moved to the rotary in front of the castle. We had a great view of Tinkerbell as she flew out of the castle.
Good luck!