Help with this network...

It looks like the require you to pipe everything via proxies to get out to the Internet and block everything else with their firewalls. Firefox is the easy one. It doesn't use the OSX Proxy settings from System Prefs, so duplicate the setttings on the leaflet into the Firefox preferences and that will work I also know that MSN Messenger allows you to set a SOCKS proxy so you might be able to do the same with Adium if their proxy server runs SOCKS as an option.

Mail is more difficult. You'll have to find out whether the university allows POP3 or IMAP mail collection from the Internet. If they don't you'll either have to set a forwarding on your existing mail account so that all incoming mail gets relayed to your mailbox on the University's email systems, or resort to WebMail (not e-mail as I previously posted).

 

You can set proxysettings in Adium. I use it to connect to my AIM and jabber
accounts. You can tell it to use the system proxies or use specific proxy settings. It's hidden in the preferences, account -> edit, proxy. settings.