First, the good news. This book does contain plenty of useful information. If you're looking for a guide that focuses on Boulder, Estes Park and Rocky Mountain National Park (as opposed to a general Colorado book), it may be worth getting.
Now, the bad news: this book will not actually help you find any of the attractions that the authors describe. For some mysterious reason, they did not seem to consider that it might be useful to include some maps showing where everything is.
The book has a grand total of two (2) maps: a very general highway map of the Denver area, and a very general major-street map of Boulder. Neither has a key to any of the hotels, restaurants, shops or attractions mentioned in the book. I kept flipping through the pages looking for the detailed map of Downtown Boulder, or any map at all of Estes Park or Rocky Mountain National Park. Unfortunately, they just don't exist--to find anything, or to plan an excursion, you'll need a different book.
Other guidebook series (such as Moon or Lonely Planet) generally do a better job providing usable maps than the Insiders' Guide. But even the Insiders' Guide for the Oregon Coast, for example, has enough maps to get by. But Insiders really dropped the ball on Boulder. Hopefully they'll pick it up for the next edition. If they can find it.