[JerryG]

Yo, IC,
One copy of the book is sufficient, but make sure you have lots of sticky notes in the bag with the book. I take the book with me in the car all the time. If I have to wait for some reason, I open the book and go on the hunt. If I run into something I need to remember, I tag it with a sticky note and sometimes write something that usually turns out to be unintelligible later.
The book, however, is constant and satisfying. Once I figure out what my question is (that's the hard part), the book provides the answer (or Kev Carter points me to it).
We need to talk.