Hunter Davies doesn't take the Beatles phenomenon nearly as seriously as most writers, despite the fact that he wrote the only authorized biography of the Fab Four back in the 60s. This book is part biography and part personal memoir by Davies (recalling the times and some of the fibs surrounding the Beatles).
The Quarrymen were John Lennon's skiffle band, the group Paul McCartney went to see on July 6, 1957 (when he first met John) and that Paul and George subsequently joined, which changed everyone's life forever. The book focuses on the original Quarrymen (Rod Davis, Len Garry, Eric Griffiths, Collin Hanton, Pete Shotton and John Lennon) and follows them through to their "reunion" minus John in the 1990s. It is principally interesting for (1) placing the Beatles' phenomenon in the context of the place and times, and (2) illustrating the amount of hysteria that continues to cling to the Beatles' legacy to this day. It is NOT a prequel to Davies' Beatles book, nor is it "essential reading," but it is definitely fun.
Plus, it's interesting to look at the Beatles' vague memories of the Quarrymen in Davies' Beatles book and then to compare those with the vivid memories that the Quarrymen themselves have of their close brush with fame (including the fact that they couldn't afford to have a tape made of their 1958 record (which everyone except Quarryman Duff Lowe, who had it, had forgotten about) -- it cost about one pound more than they could scrape up between them!).