How do I get started developing a Premiere Pro plugin? I have Premiere Pro CS3 and a working knowledge of VB.NET. (I have experience with a number of other languages that I can use to get around if need be.)
Is there an SDK that I'm looking for? Do I need to contact Adobe to join a developer program of sorts?
EDIT:
Silly me, I've found an SDK on Adobe's site. Where can I find an API or reference?
There's an SDK, no signup needed. http://www.adobe.com/devnet/premiere/sdk/cs3/. The API docs come with the installer.
Edit (more info re: comments):
I don't know of any really good tutorials out there. The best way to get started would be to try compiling some of the examples that come with Premiere SDK [using VC++, they all come with project files], then see if they work as expected. There's a "Simple Video Filter" plugin in the examples that might be a good starting point.
It would probably also be helpful to get the After Effects SDK, as there are similarities between the two. From Chapter 10 of the AE CS3 SDK Guide docs:
Adobe Premiere Pro supports the After Effects effect API. As of version 2.0, Premiere Pro offers a thorough host implementation, the key omissions being 3D-related calls (auxiliary channel information, cameras and lights) and other utility functions provided by After Effects’AEGP API.
If you haven't done a lot of C++ yet, C++ in Action is one of the better [online, free] introductions I've seen. It might be too basic, but some of the plugin API stuff is pretty hairy, so a separate non-Adobe-API-related place to brush up on the language is probably a good idea.