Go. Read. This. Book. Now.

This is a must-read for any developer who wants to know Javascript better. This is the book that taught me everything I know about prototypes, method decorators, and functional programming in Javascript. Sure, I'd read countless other Javascript books, but Reg has a way of explaining things in a way that connected the dots for me. This is probably the only programming book I've re-read cover to cover a dozen times or more.

I'd also strongly suggest you throw a few bucks Reg's way for the ebook (PDF, EPUB, MOBI) version of this book. I only know Reg through his writing, but he sounds like a great guy. The fact that he's releasing this gem for free is pure madness on his part.

If you couldn't yet tell, highly recommended.