Instructions on how to associate with an AccessPoint under your operating system.
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