Sadly, the biggest "friendly" resource is gone, which was www.donsbulbs.com. You can go through 49 CFR Part 564 and get the specifications (including mechanical) of bulbs allowed in the U.S., though. Tedious, for sure!
this .PDF covers the other bulb types used in UNECE signatories (and Australia and other places). Between my two references (found in a Sticky in the Automotive forum), this should cover every regulated bulb type.