First of all welcome to Linux
If your card is listed in
you're halfway there, from then on it depends on your distro, I'm not familiar with Red Hat , but it should be fairly simple.
As usual to begin with you need to get ready for the task at hand
You will need to know what module you need for your card (see url above)
then you will need your IP settings if you are using just the modem you will need to use PPPoE
if you use a router,then you need to know your
ESSiID that is your station identifier a name you gave to the router when you set it up
also you need to know what channel it is using
what mode are you using ( ad-hoc, managed, auto,etc.)
finally when you get to a point that stumps you,get all the information you have and post back.
remember the more info you have the easier it is to pinpoint your problem.