LL Rules -vs- FED rules

[Buckeye12]

I was asked to umpire a Little League tournament this weekend played under "Official Little League" rules. I told the tournament director that I was unfamiliar with these rules but he said that he will go over main points with me before the tournament begins. I was wondering if anyone could help me out with some of the differences between LL and FED rules. Any help at all would be greatly appreciated. Thanks