This MacObserver article also tells you how you open the iTunes Port (3689) and keep Mac OS X Software Firewall still active.
This port also needs to be open if you want to share via Rendezvous and Mac OS X Software Firewall is on. I was having problems with this until I read this article that came via PGant, thanks for the link.
Man, 5 users streaming high quality mp3's adds up to a lot uplink bandwidth. Most ISP's don't like the uplink to be very high. I had a "burp" in my usage around Christmas that spiked my monthly upload at about 60GB's.
I got a couple of emails from my ISP, but they didn't shut me down... I was quite furious that they singled me out until I looked at my numbers for the previous few months...
Wow, I didn't think that the sharing would be as good as it is now. It'll be absolutely great in that you can have all your songs at home and listen to them at work if need be or vice versa. Is there anyway to stream the lists onto a PC as of yet, as during the summer I have to use a PC, and if I can play my music from my Mac, it would be 10 times better.
It's fairly easy to stream a particular MP3 to a Windows machine (provided you can determine the "magic url" iTunes generates for that particular MP3). I'm not aware of any software package that allows you to browse through all of the tracks available on a particular machine, though.