How far are you going and are you going to be cycling all year round in all weathers? Cyclocross would be the best choice if you're going a fair distance all year round. If you're a bit more fair weather a standard road bike would be fine. Hybrid bikes are good, but not so good on long distances - I like mine, but after a few good rides on my new road bike, it's been relegated to popping to the shops. If you're going a very short way then look at a proper city type bike like the ones the Dutch ride.
Whatever you go for, enjoy it! Cycling to work is a fantastic way to start the day. I would suggest getting into a daily routine early on rather than trying once or twice a week. So much easier to carry on long term if it's what's you're used to.