The 12 Simple Secrets
of Microsoft Management is another easy read. It has interesting insight into the way Microsoft is run on a day-to-day basis.
Many of the principles that guide the company stem from two over-arching tenents:
First, the MS hiring practices. Microsoft emphasizes determining how their candidates think, rather than what they think. Problem-solving questions are the norm with the emphasis on the process of how the answer was determined rather than on what the actual answer is. They hire the best, and won't make-do with weaker candidates. This practice results in an implicit ability to trust one's co-workers to solve problems in order to complete a task.
The second guiding tenent can be summarized as "the person with the most information makes the decision." If that person is an intern, so be it--Microsoft hires the best people, remember. The flat hierarchy results in decisions being made quicker, which in turn results in a company that is more strategically agile than most of its competitors.