Hi,
you want a layer to stop the wind. Then you want some insulation.
You will want something to cover your ears, which can be tricky with a helmet. I remove the padding on an old helmet; put on a balclava, and then the helmet. If you have downhill ski gloves, they work nicely. Up top, layering works. I have problems with the pants situation because I have 26" legs. That's cold, they are closer to 27" when I ride. I have yet to find a perfect solution when the temp drops below freezing. A lot of guys use old style pedals and big boots in the winter. I got some neoprene shoe covers, but I don't know how well they will work. The Icebike.com site is good.