If your "cold" temps are around 45°F, all you'd need are a pair of tights, a long sleeved jersey and a jacket. If your hands tend to get cold even in warmer temps, you might consider a pair of mini-gloves (those one you can buy for $1 at Walmart) under your regular cycling gloves.
If it gets a bit colder than that, you might consider a sweatshirt over your long sleeved jersey, and possibly light nylon toe covers or booties.
When it gets below freezing, that's when you have to start to get serious about what you wear out there.
Last February I rode a century. The ride started out at -32C/-25F and reached a high for the day of -25C/-12F. Here's what I wore:
- balaclava http://www.mec.ca/Products/product_...D=1065145178773
- helmet (Bell)
- sports bra
- longsleeved Coolmax jersey (MEC)
- longsleeved fleece jersey (Nashbar)
- "fall/spring" vented jacket (a fabulous jacket I got from Nashbar - but I see they don't sell it anymore . . . pity!)
- windproof mitts or ski gloves (I had to change these every so often to let one pair dry a bit) (Canadian Tire Where else! )
- cycling shorts (Nashbar or MEC)
- tights - fleece lined (Nashbar - very comfortable in cool weather)
- non-cycling knee length shorts
- "metallic" socks
- wool socks
- Sorel boots
I also used little heat packs in my boots to help keep my feet warm.
On less cold days, I wear my regular cycling shoes with neoprene booties. I did a 200K brevet in November 2002 that started at -12C/10F and peaked at 0C/32F with wool socks, regular shoes, and neoprene booties. I used those heat packs for the first 50K on that ride too.
I don't like to wear anything over my face - even in the cold temps I've mentioned above (and I've commuted to work in temps down to -40 too) - because scarves, masks, etc. cause my glasses to fog up, and I don't think that covering my face is really all that necessary. The skin on your face is pretty tough because it is exposed to the weather all the time. In the really cold temps, if I'm going to be out there for a few hours or more, I will smear my face with Johnson's & Johnson's Daily Protection Cream to prevent frostbite.