There is no shortage of books about Wagner and The Ring of the Nibelung. I’m listing here ones I’ve read and can recommend and ones I’ve had recommended to me but may have not got round to yet. Links are to each book’s page on Amazon UK.
Books About Wagner
Richard Wagner: The Sorcerer of Bayreuth by Barry Millington (2012)
Published for the 200th anniversary of Richard Wagners birth, and written by one of the most distinguished Wagner scholars in the world, this in-depth and highly readable account of Wagners life, work and times will be the book of the bicentenary. Richard Wagner (18131883) is one of the most influential and also one of the most polarizing composers in the history of music.
by Michael Tanner (2008)
Tanner’s fascination for the relationship between music, text and plot generates and illuminating discussion of the operas, in which he persuades us to see many of Wagner’s best-know works afresh. His passionate and unconventional analyses are accessible to all lovers of music
Wagner, The Man And His Music
by John Culshaw
This is an older book, published in 1978, but a good read if you can find a copy. They come up quite frequently fairly cheaple on eBay. “Presents a lively text and over 150 historic photographs and drawings – many in full color – to document the life and work of the master of Bayreuth. Also included in this brief but authoritative biography are the stories of each of Wagner’s operas with notes on the casts and conductors of the world premieres and Metropolitan Opera premieres.”
Wagner: A Documentary Study
by Herbert Barth (1975)
Another book you’re more likely to find on eBay but worth digging out for the massive number of illustrations. “It is to be hoped that the academic public will not be deterred from paying proper attention to this splendid volume because, being on the grand scale and having such a magnificent and varied set of illustrations and facsimile reproductions, it might superficially appear as a coffee-table book. In fact, it is a publication of great scholarly interest for anyone concerned either with Wagner alone or with his relations to German culture and society in the larger context.”
Books About The Ring
Wagner’s Ring: Turning the Sky Around;
An Introduction to The Ring of the Nibelungby M Owen Lee (2004)
A short concise appraaisal of The Ring Cycle, expanded from the author’s popular intermission talks during Met Opera broadcasts.
Wagner’s Ring of the Nibelung: A Companion
by Stewart Spencer (2010)
This is the first literal, word-for-word translation of Wagner’s epic masterwork with the full German text. Stewart Spencer’s version is at once reliable and readable, adhering closely to the original verse form and to Wagner’s poetic intentions. The German text is given in parallel, and Spencer also contributes illuminating footnote and an introductory essay.