Well the way our (granted ancient) 2600 chapter one went was this way. A few meetings aforehand we had volunteers for the following tasks:
Who would burn CD/DVD's
Who would be there to install
Who could bring a fileserver there to dole out .isos if nobody burnt it, or ones were out being used already.
The third came out to be the best option, since all we needed was a server with a few nic's and then we could have one nic do a few people only (not too bogged down in the end). Plus no CDs were wasted. The trick was getting peeps up to speed on how each (and every distro was different in its own way ... ) distro did netbooting the install image.
We didnt have web acccess and were pretty much stealing Wifi from some store (was at a mall conference room). So all the lan gear was needed. Luckily some dude brought in a spare 24 port hub from work (work actually had a few employees and bosses show up to check it out) and the cabling and spare nics (and a few were needed ...).
Aside from that it wasnt rocket science. Just have the major ones plus whatever you wanted to grab. We had (at that time) alot of Slack, Red Hat, and Debian. A few BSD nuts were there too doing Net and Free BSD installs. It was a long but fun night.