For the past year or so I have been using a D-Link DWA-125 wireless N 150
USB adapter. However, it is not N 300.

When I got it I was using Ubuntu 10.10 and I had go install a driver to get
it to work.

About 4 months ago I done a fresh install of 11.10. When the CD boots up,
right at the start of the install it ask for which WiFi and password. That
is all it needs. I don't know if 11.04, the first Unity, comes with the
drivers.

As far as I know D-Link still does not support Linux. Fortunately Ubuntu
supports D-Link.