How to dress for biking 3 miles to work in 40°F (3°C) and below so not to sweat to much but still keep warm
It depends a lot on you. I live in Illinois and I'll go out in a T-shirt and shorts in the 40's for bike rides. 

But if you want some additional warmth in the around 40F and 3 miles, I'd say maybe some thin gloves (I have a set of Underarmour coldgear running gloves which are useful for longer rides in the 30s) and a hoodie - you might be cold for the first 2-3 minutes but then you'll feel fine. If you find that a hoodie leaves you cold for the whole ride, maybe add a wind breaker with some ventilating holes. 

In general, you shouldn't dress enough to feel warm when you're getting on the bike. You'll generate some extra heat, so in most cases, the right amount of clothing will make you feel a bit cold for the first few minutes. 

A ski jacket is way too much bundling for riding in 40 degree weather (given that its probably overkill for even just standing outside).