Can anyone suggest a book or web site that discusses proper road bike posture and hand positioning (preferably with pictures / examples)? I just started riding my first road bike last weekend, and I'm still trying to figure out where to keep my hands in order to ensure proper posture, quick access to the brakes/gears, while minimizing numb hands and butt. I've been riding a hybrid all summer, which has a more upright posture.

Any tips you might want to share would also be appreciated. The bike was fitted at the bike shop, and the fit feels good. I'm generally comfortable on the bike, but I'd like to optimize my posture for longer rides.

Thanks,
Tim