I've hosted a couple of parties of 8-10 people. One problem that seemed to come up a lot (especially since LAN gaming doesn't happen as often as it should

) is that people spend way too much time trying to patch their systems and get maps, etc. I usually set of a POS non-game box as a fileserver to host the patches and maps that are relevent to the evening's gameplay.
Usually with a smallish group like that we try to stay focused on one or two games. A combination of Unreal Tournament and Red Alert seems to feed the cerebral and reflexive halves of the brain.

For connectivity I use a 5 or 8 port switch for file and game servers as well as to connect to hubs. I also use a 24 port Cabletron 10BT hub with a 100Mb uplink to the switch for game clients.
Don't forget lots of beer and finger food (no cheetos). Friends and I also usually get burritos as part of our ritual at this Mexican joint that's open until 3am. Gotta fuel the fire before getting back to it!
Have fun gaming!
For the network gurus- if a MAC address is spoofed, what prevents packet sniffing if the traffic is redirected to the spoofed address?