Probably about what you might expect. Hormones and egos. Everyone was sleeping with each other leading to jealousy and fights. There was some dabbling in drugs, and Dustin Diamond was driven to alcoholism by no one wanting to be his friend. Or something.
I believe after the film came out he...
Some cheesy made for TV movie looking at "the true story" behind the show - based on Dustin "Screech" Diamond's autobiography where he basically trashed everyone.
Hopefully it'll air in the UK soon.