I've been stuck on the backend for years now, working on webservices, DBs, SDKs, APIs and all that jazz, and so that's an area that I have a decent grasp of, but I've absolutely no clue about how the frontend works.

What's a good place to start for a backend monkey like me who wants to learn the best practices, latest technologies and the philosophy behind modern web page design and its interaction with the server? I want to be cool like all of the other javascript kids.

Thanks!