Well you will definatly needr enough network equipment to hold every body. Then if you arnt up to the task of networking find some one who is willing to get headaches

If you have multiple games (which all lan parties should right?) I would recomend a server a game. But more importantly have each game on its own subnet and seperate the subnets with router(s) This will help keep trafic flowing smothly and hopefully make it run faster Second you need enough Router(s) and Hubs to hold every one. Best luck i have seen there is having people RSVP. Also make sure you can have that much power flowing to you and not overload your circut breakers or anything. Also some spare cable and RJ-45 connections with a crimper isnt a bad idea... then Food

Ill try to think of other things. GL
-: phenious :-