What are the essential resources for learning the fundamentals of LEGO building? After years of buying and building LEGO sets, my six-year-old son is tearing through the first level of the Master Builder Academy. He's fascinated by micro-building, and generally seems liberated after learning some of the fundamentals of LEGO design and building. 

There are so many books and blogs, but many of them just show (fantastic) finished projects. I'm looking for the best published material (of any era), websites and individual blog posts that teach techniques and ways of thinking about building with LEGO -- that show and tell.
I'd particularly recommend The Unoffical LEGO Builder's Guide. It covers all of the basics and gets into many of the more complex building techniques.

If you're interested in getting right into the details, The Unofficial LEGO Advanced Building Techniques Guide by Didier Enjary covers a wide variety of building techniques and is freely available. I don't know a lot about this document, but I first came across it on The Brothers Brick.