This book is amazingly accurate! I spent my twenties figuring out what I could have simply read in this book, were it only written sooner. Based on when you were born, you can read about what your life's challenges and main theme of learning will be. Why are we here? What is our purpose on this planet? If you already have any of the other books in the series, this is a must have too. If you don't, I'd recommend starting with "The Secret Language of Relationships" or "The Secret Language of Birthdays." A "must have" for anyone with even a casual interest in the subject of astrology, karma or spirituality; It is the ultimate sourcebook to help shed light on your destiny.
There's quite a few negative reviews of this book on here that say "Don't buy this book because only 8-10 pages will actually pertain to you in particular." While this is true, I think this criticism is a bit narrow-minded. That's like saying a dictionary sucks because it "defines all these other words that you'll never ever have to look up in your entire life."
Part of the appeal of this book is that its information applies to everyone. If you want a book that only talks about you and your life, I'd suggest buying something else that only deals with your zodiac sign. The Secret Language of Destiny is meant more as a coffe-table book, something used to spark discussion between you and some friends. It's really fun to say to somebody, "Hey, here's what this book says about your destiny. Does any of this apply to your life?" Most of the time the karmic paths (which are base on birth date and year) are eerily accurate. I wouldn't say they're constantly dead-on, but I think that for most people there'll be enough similarities listed to at least get them thinking.
A good pick-up if you get a kick out of seeing if the personalities of your friends match up with the personality profiles of their zodiac signs.