I debated if to give this two or three stars, and I'm giving it two simply because I expect better from the For Dummies series of book.
First for the good stuff. I'm not sure you can get another book for the TI-89 for this price that will help you get started with the calculator. And I did learn stuff from the book. So if you just spent $150 to buy the calculator, and you need an inexpensive book to help you get started, this is the book.
But the bad is this. This book seems to me to have been a rushed job. I don't believe it was fully edited and critiqued before it was published. A lot of words were wasted repeating the same information over and over. In part three of the books it seemed like each chapter had a section on analyzing that was just like the section in the other chapters. Also, it seemed like the Zooming functions were re-explained a lot. In chapter seven, pictures are shown of graphs that where graphed on the calculator, but we are not give the formulas so we can graph it on our calculator (I used the formulas .5x-sin(x) and 1/3+x, but not exactly the same as what's used in the book), making it hard to follow alone with the instructions the book is giving. Much the same thing is done in chapter 20. I never did figure out chapter nine, but maybe I don't know enough about sequences.
Although the book was helpful, almost everything in it could have been explained better. And I wish more time would have been taken explaining the calculator itself, such as the differences between it and the other TI graphing calculators, some basics about how the applications that come with it work, and the meaning of the stuff you see when you use the 2nd & MEM keys. It's an okay starter book, but with a little more effort it could have much, much better.