I understand that a wireless card allows you to connect to the internet without cables..
But after purchasing the wireless notebook card, do you have to still sign up with an "internet provider" or pay any monthly fees?

Here's some links for your reference (sorry, some of them are trying to sell you their service, but... ):

http://www.wirelessinternet.com/release_-_wireless_security.htm

http://www.ositech.com/CellData/Learn.htm

http://www.intel.com/personal/computing/emea/eng/do_more/wireless/going.htm

http://www.txol.net/services/internet/wireless/wirelessfaqs.html

Or perhaps an eBook from Amazon?
http://www.amazon.com/exec/obidos/tg/detail/-/B00005US4S/104-0429713-0055147?v=glance