Instructions on how to associate with an AccessPoint under your operating system. Warning, this is currently a work in progress, and very much incomplete. --ForrestEnglish
Windows
Windows 98, ME and 2000 each use applications shipped with your card that you should install and use. I will fill each of these out as I have time and cards 
Lucent / Orinoco / Wavelan
Linux
You should be able to define what network your pcmcia card connects to in /etc/pcmcia/wireless.opts, however some cards firmeware ignores this. Listed below are some commands that will allow you to change network association.
BRBR Connect to a standard InfastructureMode access point:
iwconfig mode managed essid network_to_associate_with
If you want to connect to a WEP network, you will have to enter the key (key length and data are dependant on the network): {{{iwconfig mode managed essid network_to_associate_with key key 1122334455 }}}
To connect to an Ad-Hoc network:
iwconfig mode ad-hoc essid network_to_associate_with