—-Check the publication date; the information inside will be a year older than that date.
—-See who wrote the book: some guides written by locals delberately omit great places (we did when I worked on guides abroad, as who wants a bunch of tourists in their special restaurants.)
—-Check if the book has information on women travelers: Lonely Planet have a section on issues for women
—-What is the budget level of the restaurants and hotels? Are they all US chain hotels?
—-A reading list tells you the author is talking to smart travelers.
—-Last but not least, can you carry this book? Lighter and smaller is better than heavy and beautiful.