Most of the rule book is rules for character creation and combat. If you already have your character made up, you can get by with borrowing someone else's book.

What the game's like depends a lot on the Dungeon Master and the adventure he has prepared. It could be a lot of "roleplaying" that consists of your characters talking with NPCs with short bits of combat in between, or it could be a hack-and-slash dungeon crawl in which you kill monsters and take their stuff.

As for a video of people playing, although it's not exactly what you asked for, I'd recommend this.