I'm sure this is covered in other threads, but here goes...

Hands: I don't need more than normal fingerless gloves until it's in the 30s. Then I wear fingerless gloves on the bottom and on top a pair of PolarFleece gloves you can get at Old Navy really cheap.
Arms: Below 55 but above freezing, I wear arm warmers. They're great and some are even on sale on TE right now!
Body: Below 55 I wear a light vest. Below 40 I start adding a light jacket or another layer.
Legs: Below 50 I wear a light pair of running Spandex over my normal bike shorts. Closer to freezing I wear a couple layers of those same pants. I'm a big fan of layering up on the pants, although I've never used leg warmers, so I can't speak to those.