When I went it was pretty relaxed. There are lots of safety checks and fail-safes to help ensure that nothing bad happens. First time jumpers will jump tandem with an experienced professional. Typically the pros are a close knit group of adrenaline junkies that just know what to do an when. However, the rules to become a professional are pretty stringent.
As a side note, you more likely to die in an accident on the way to the jump site than you are on the jump itself.