Happened to notice today a new Mapping Extension on MozDev.org today called MapFox, so I decided to try it out.  MapIt was the mapping extension I was using previous, but it was pretty useless.  It didn't use Google Maps (which is amazing), and it didn't have built in support for Canadian address.
MapFox has all of these, so give it a try.  From the extension options you can put in your address which will give you directions to a selected address.  Just enter your postal code where it says zip code.
After its all setup just highlight the address on a webpage, right click and select MapFox for a simple map of the address, or MapFox Directions for directions from your default address to the highlighted address.