Experience, Continued
My suggestion to those of you that haven't hosted a LAN before is to start out small and work your way up to larger events. Yes, starting out small might not seem as glamorous as some of the larger LANs you've seen covered here on THG, but those guys had to start somewhere. The spirit that caused the first gamers to hook their systems up in the first place is the same that grows LANs today.

A few friends gaming in a one room apartment.
It is all about the experience and when you do it right the first time you don't have to work as hard the next time attracting people to your event. Endeavoring to attract 100+ or even 200+ people for your first LAN can and has been done (albeit far and few between). However, testing everything out first on a smaller LAN will insure that when the bigger event comes, you will be ready for it. It is far better to be safe than sorry. It is a lot easier promoting something that was fun for everyone than trying to salvage the people that went away with distaste for your event because of a lack of power, network, or some other key item. Fun is the real reason people host and attend LAN parties. Keeping that as your ultimate goal will show up in the growth of your next event.