What is required to get a Dell Inspiron 5000e running on a wireless internet connection?

I have a Dell Inspiron 5000e laptop with no PC card in it. I would like to know what I will need in order to establish a wifi internet connection.|||You can buy a Wireless card at same place where you buy the wireless Router(circuit city, best buy, online, etc) Setting up a wireless connection is a pain in the butt or at least it was for me.