I've read this. It's really good. It's published by a company called Cadogan who are a travel publisher - like Fodor or Lonely Planet if you haven't heard of them - so this is a travel book. You don't get places to stay and all that, but you do get lots of descriptions/evocations of different places around England. That might put some people off. If so, that would be a shame, not least because Lyons is a good writer and clearly a Tolkien fan.
You get a very strong sense of the English landscape and of why Tolkien loved England so much and what it was that he loved, ie, it's (lost) histories and myths. What Lyons does is visit, say, the Berkshire Downs, tell you what it's like to be there and - more importantly - explain the Tolkien connection, how Tolkien might have seen the area and how he used that in his writing. So the chapter on the Downs tells you about Tolkien's love of Mercia and Mercian literature, Viking burial mounds in the area, how Anglo-Saxon mythology used to be associated with features of the landscape before the Norman conquest, the various dragon-myths surrounding the White Horse, medieval festivals, King Arthur, etc, etc - all the time referring back to LotR and finding connections.
In one chapter, Lyons discovers a possible source for Tolkien's inspiration for hobbits and hobbit holes, which I hadn't heard before.
Not all the chapters are equally successful, but on the whole it's a fascinating look at one part of Tolkien's inspiration. You end up understanding how and why Tolkien felt so passionately about England and how he celebrates it in Middle Earth - there's a lot more connection than I thought (ie, if you'd asked me before, I'd have just said The Shire).
In a way, because Lyons oviously shares that passion and conveys it well, you feel a bit closer to Tolkien than you do with a lot of books about him.
This has turned into a review, so I'll stop.