The author is an expert in their field. Check their credibility by looking for details about them via a Google Search, try and locate a CV, or ask your Professor if they're familiar with the author's work.
What institution(s) or organization(s) is the author affiliated with?
Have they authored other publications in their field?
Note the publisher of the book; often university press or professional organizations publish scholarly content.
Are references or works clearly cited? Does the text contain footnotes?
Johnson steers her readers through the massive amounts of geographic information available through the Internet, satellite technology, and other sources. In addition to map basics she covers geographic information systems, geographical standards, organizations, instructional resources, commercial publications, and careers in geography. The titles and items chosen for inclusion have been deemed the best by users and librarians, are fundamental to understanding specific kinds of information resources, or illustrate specific points or outputs by publishers of interest.