We ended up having a rather large room, with machines set up all around the perimeter. Remind folks that they are representing the Linux community, and that their time and work is really appreciated. Point out two or three of the members that can act as back-up. It's hard enough for most hackers to wake up before noon, let alone get a balanced breakfast. Try to have one or two people who can get together orders for food and go out and get it.
Nothing goes with silicon better than pizza.
On some machines with older an older BIOS, boot-block programs may be required for the proper operation of Windows. If the machine in question needs to continue running Windows, create a boot floppy instead of using LILO on the master partition. When in doubt about whether a large hard drive has special boot-block software loaded, load Linux, create a boot floppy and do not install LILO in the master boot sector. It might not be a bad thing to make sure that the system boots as it is. NOW I lucked out and had 3 installs where they didn't care about keeping Windows or the old version of Linux already on the system.