Replying to What goes into putting on a Rail Jam?

So my buddy and i have a school assignment to put on a major project or perhaps an event.  We are both skiers so we figured we would do a ski/board rail jam at our school.  There is a decent crowd of park rats at our school, and definitely a ton more in the area.  I have read from other places that yeah its alot of hard work etc but we are willing (and forced) to make it happen.  We are wondering what really goes into putting on a decent rail jam.  We already have a local shop willing to sponsor and supply prizes.  we have a set up planned out which consists of probably a few metal rollers (like DNA) as drop ins and around 3 features.  Turf landing and probably arena snow inrun.  We have sort of been planning for a while, but it needs to happen beforel ike the second week of june.  What kind of insurance/permits would we need?  Thats our main question right now.  we have talked to the principal and he has allowed us to do it, but there are liability issues.  Night or day?  Promotional ideas to make it bigger?   Any help is appreciated!