Search "gloves" in the title and I bet you get quite a few threads to keep you busy (assuming search is still working).

I bought $5 poly-pro liners to wear inside my $5 hardware store winter gloves and they were good at 20F the other day.

Also, I ride my mtn bike on the road sometimes when it's really cold - less windchill, and I don't care about speed this time of year.