The basic rules described to me by Laura Barclay (read that as a disclaimer on my part ;) are:

1. Basic Concept: Two teams on a rectangular field with opposing endzones. Teams score by catching the disc in their endzone.
2. Beginning Play: Each point begins with teams lining up in their endzones. The team that just scored (or the defense) throws the disk to the offense (vernacular is "pulls disk" ?).
3. Play: Teams move the disk up the field by completing a pass to a teammate.
• You can take one step but you CANNOT run with the disk.
• A thrower (person with disk) has 10 seconds to throw.
• The defender guarding the thrower counts out the 10 second stall.
4. Change of Possession occurs when the disk is thrown out of bounds, dropped, or blocked by a defender. The defense immediately takes possession of the disk and becomes the offense.
5. No contact is allowed between players (unless they are both getting into it). Picks, when a player runs near other players in a way that keeps his defender from following him or forces a collision are prohibited. Defenders are not allowed to touch the thrower or knock the disk out of his hand.
6. Fouls: When a player knocks into another player or in some other way a foul causes a change of possession, the offense keeps the disk.

There are two types of defense: man on man and zone. Zone involves a few players "cupping" around the thrower and the other players in a zone defense covering the receivers. Offensive plays, well, the two primary ones are stack (where players form a "chain" up the field and one of the players cuts out to get available) and zone (... I have no idea how this one works holmes).