I just did a 30 mile ride in the midwest and the temp was a bit above freezing. It's all about layering. For a jacket I'm fine with a few layers: base layer, pile vest, pearl izumi softshell, and a pearl izumi barrier jacket. I bring a waterproof shell in my bag but I don't like wearing it unless I have too because it interferes with sweating.

You might want to check out Sierra Trading Post; that's where I picked up my PI softshell and barrier jacket. It's a good place to find base layers as well.