I'll agree with K Bert to a point. However I started my MBA on the Open University a few months ago and read this book a few months before and actually found it a nice introduction.
Granted it can't cover every topic in massive detail, but what it does give you is a nice framework for (what I assume to be from what I've studied so far) an entire MBA, granted possibly one in the US. However most of it is pretty identical so far.
For the price I'd recommend anyone contemplating buying this book to do so, I found it very useful, well written and quite easy going.