SilverSnow: yes, as oddness said, Smeagol, otherwise known as Gollum, appears only briefly in the Fellowship of the Rings. His appearance is little more than what you saw in the movie. He plays a much larger role later on, so don't worry.
Oddness: the reason you saw Sauron in the beginning was because that was thousands of years in the past from when Frodo and the Fellowship set out on their quest. He still had his physical form, but was destroyed as you saw by Isildur. His spirit, however, lives on in the ring. He will regain physical stregnth again once he regains enough power. that whole thing was like a little background as to the origins of the One Ring, the ring of power. And yes, his armor did look sorta like a Power Ranger's costume, but more sinister, and not as cheesy.
abe22: Frodo had the mithril armor on, which is vurtuely impenetrable. He was gasping for air as if someone had punched him in the chest, a very big wallop. And he's not a kid, he's a hobbit, just to clarify things.
