Here is a primer for business people wanting to know what all the terminology in Agile means to them: What You Need To Know About Agile (PDF).
It maps the various agile practices like TDD, Iterative Development, Retrospectives, Backlog, Continuous Integration, User Stories and so forth onto common business categories like Increased Quality, Process Visibility, Repeatable Process, et cetera, in other words, shows you what sort of business issue each agile practice is aimed towards. I don’t think it’s perfect (veers off to a house-building metaphor, for example, which I don’t think is completely successful). It doesn’t also contain a section explaining the overall reasons and philosophy for Agile development. However for a manager who is thinking about Agile, and is confused about some of the jargon they’ll hear from experienced agile practitioners, it does a strong enough job at mapping the practices onto traditional process management categories for me to recommend its reading.
