This question was asked in another place but I thought I would mention it again here.

Arm warmers work great. You can wear them in the morning and peal them off when it starts to warm up. They also are good for running.

Leg warmers are nice also. You can wear your favorite bike shorts with them and once your legs warm up, peal them off. You can also get tights with a pad or put your running tights over your bike shorts but for long rides chaffing may be an issue. Also, if it starts to warm up and you are in padded tights, it can get hot and sweaty.

Shoe covers are a must have. Most of the shoes are pretty well ventilated to keep from overheating but in the cold this is not good. Some people use duct tape to cover the vent holes but the shoe covers are a better option IMHO.

Fingered gloves are great. If it is really cold I use ski gloves. Otherwise I have some mesh gloves with a built in wind cover that I can pull over my fingers when it gets really cold.

I also have a vest and wind breaker. The wind breaker usually comes off fairly early and is light enough to tuck in one of my rear pockets.

A beanie or head band to cover the ears is also helpful.

Better yet is an indoor trainer and a treadmill. (Or use the treadmill at the Y)