"... Nearly 170 pages [in The Mammoth Book of Chess] are ... devoted to various chess openings. ..." - Steve Goldberg (2010)
https://web.archive.org/web/20140708093123/http://www.chesscafe.com/text/review756.pdf
(Lots of illustrative games included.)
Note the number of illustrative games apparent in the samples from some other books:
http://www.gambitbooks.com/pdfs/Understanding_the_Chess_Openings.pdf
http://www.gambitbooks.com/pdfs/FCO_Fundamental_Chess_Openings.pdf
For a first book on the subject of opening play the book to get is "Discovering Chess Openings" by John Emms. It confines itself to a treatment of fundamental opening principles (i.e., it is not concerned with attempting to present or analyze all the openings and their variations in any organized or comprehensive way).
Beyond the Emms book for its treatment of fundamental principles, for a more detailed survey of all the major openings and their primary variations in an organized but succinct overview presentation, I would choose from among the following three books, also previously mentioned, each of which do a good job in that respect. In increasing order of the depth/details of their treatment of the openings, they are...
Winning Chess Openings by Yasser Seirawan
Back To Basics: Openings by Carsten Hansen
Understanding The Chess Openings by Sam Collins
On the other end of the "details" spectrum for an opening reference (i.e., very detailed, and excellent treatments) are - "FCO Fundamental Chess Openings" by Paul van der Sterren, (for the best single-volume reference) and "Mastering The Chess Openings" by John Watson (an outstanding four-volume reference).
There are of course many good opening books that go into detailed treatments of specific openings to various degrees, but for the purposes of a reasonably succinct and readily digestible first exposure to the openings for the beginner-novice, the books specifically mentioned would accomplish the mission nicely I believe. By the way, I own all of the books discussed, and understand and appreciate the differences between them very well.
As a peripheral comment, I would avoid the book Mammoth Book of Chess by Graham Burgess previously mentioned, which is a general treatment of chess, and a relatively poor one (IMO) at that; its focus is not chess openings, although it does contain some relatively superficial treatment of the topic.