tmarques - as raylll mentioned in his reply, you'll first want to connect directly to the router to see if you can connect and configure (hopefully, you also updated your firmware using a direct connection to the router, as the instructions warn against trying to do this via a wireless connection). (BTW, you can download the full manual for your router here:
Super G with MIMO Wireless Router - DI-624M by D-Link - it's a bit more detailed than the documentation that came with the router.)
When you configured the router, did you disable SSID broadcast and/or enable WPA encryption? If so, you have to manually configure your DWL USB adapter - it won't connect until you've entered the proper SSID and encryption key (although it will appear as though it's trying).
Re. DHCP - you can go to the "Status" page of the router (direct connection) and take a look at the log to see what's happening with DHCP - it should at least give you an indication of whether or not the laptop is trying to connect, a lease is being issued or whatever.
For everyone - obvious reminder - please remember to add/change the admin password...