First a word of disclosure: I work in the Atlanta branch of the same software consulting company that the author works for.
Mr. Erikson's book, The Nomadic Developer, explained a lot of things about my own industry that I had never completely thought through before. For the most part I just enjoy developing software and my company affords me an opportunity to do it at a very high level.
The Nomadic Developer helped me understand how and why my company does this. The book is full of excellent ontologies of different consulting practices (which the author calls The Seven Deadly Firms), different valued consulting traits, as well as common consulting career-limiting moves (modelled on the seven deadly sins: Gluttony, Envy, etc.), as well as advice on how to get ahead in consulting and where one's consulting career may eventually lead.
The book is also an excellent guide for those who think they might want to get into consulting. The author paints a vivid picture of what the life of a technologist-for-hire is like and provides recommendations on the sort of people who would thrive in this sort of environment.
Having just completed reading The Nomadic Devloper, my main impression is of Mr. Erikson's affection for his topic as well as his hilarious observations on the perks and pitfalls of consulting. One of my favorite sections of the book is the Consultopia, in which the author dissects the sometimes cynical world of consulting while pretending to provide a lexicon of common consulting terms. I've you've ever chafed at being called a "resource," then you need to read the Consultopia. It will leave you in stitches.
The book finishes off with a chapter called "An Anothology of Sage Advice" in which various consultants give their best shots at explaining how they have succeeded and, almost as often, how they have screwed up in their profession.
The Nomadic Developer provides a guy-on-the-ground perspective on this extremely challenging and lucrative profession. I cannot recommend it highly enough.