Help with Wireless in Ubuntu

i have a Belkin Wireless G USB Network Adapter on the computer running Ubuntu/windows, and on the main computer, i have a Linksys Wireless N Router. When i used Wubi on my old computer to dual boot ubuntu, i tried to get on the internet, but it failed, but i can still get on the internet when i boot into xp. I couldn't figure out how to set up the connection, thats what i need help with.