I bought a 'TI-89 Titanium Graphical Calculator' and what strikes me the most is the abundance in overwhelming mathematical capabilities compared to a 'TI-85' of 1992. So while your becoming aware of the capabilities, it's really helpful to have this to dip into.
To complement the manual on CD PDF files this covers quite a lot of useful stuff such as vectors, calculus, (numerically and graphically) customisations, matrices, conversions, math functions, etc and does this in an uncluttered way.
The book itself is printed on good quality paper, although pages are B&W. To rate how good it is this means you may need to reread it several times?
Importantly, it shows you how to upgrade the TI 89 Titanium operating system and then install the customisable list of applications that you would like aboard. The cable to allow this IS available from T.I (online) and if you're careful and have a USB and Internet enabled computer is so easy. Even this book does not cover the whole capabilities of this 'TI-89 Titanium Graphical Calculator'. It could take a long time to explore and grow mathematically, but this book will help you get there a bit quicker.
This is a basic book about this calculator. If you need something to get you started then I would say this is just the thing. But I also say you will get the most from it if you have some experience with graphic calculators. I have found some of the diagrams not quite clear on certain points, you must read very closely and do not skip the intro.