AirPort says I'm "connected" but cannot navigate the internet

I know others have had the same problem, but I'll ask again, as the solutions are a little vague for me. I JUST purchased my D-link router and went through the painful process of setting it up via the web, because the setup wizard doesn't work on MacBooks. First of all, when setting up, I got through all of the process until it said that it was saving and rebooting the router. I pressed continued and after not doing anything for 10 minutes, a "cannot display page" came up. I tried again numerous times to no avail. While my laptop was physically plugged into the router I was able to navigate the internet, but as soon as I unplugged the ethernet and attempted to connect wirelessly, my AirPort would say that I was connected, but I was unable to open internet pages (ie. google, hotmail), as well as use programs that required the internet. Can anyone give me a step by step guide of how I can fix this. My apologies, I'm hardly computer savvy.