"... Following this is the section I would more be looking for as an application developer; describing how to interface PostgreSQL to different programming languages (normally I hate "verbing", but in this instance, it's more compact). If you were going to buy the book ONLY for this section, I'd caution you not to. It's pretty compact, as in one page per language, but it's there, and it will get you started. You have to have a knowledge of the various languages to understand the sample programs, which are offered with little fanfare or explanation. ..."
PostgreSQL is an open source database system, and the book PostgreSQL, Introduction and Concepts, is a very academic-looking book from Addison Wesley about exactly that. Not knowing what to expect, I had a quick thumb through, and to my delight realised that this was a dual purpose book - on one hand, it's a reference for PostgreSQL, and second, it's designed to help people like I was to get started with database administration and programming, because it truly is an art form in and of itself.