I enjoyed reading this and in my opinion United's early history is indeed very interesting. There's certainly a ceratin romance about how a club from 'humble' origins became the club it is.
Belton writes in an engaging style and the narrative moves along easily enough, whilst capturing some of the charcter of the period. The order of the book is chronological as one would expect and major games seemed to be covered in nice detail.
However, in terms of negatives, I didn't really understand why so much attention was devoted to Manchester derbies, which is fine in itself, but occurs to the exclusion of any other interesting or important ties that took place at the time. Very little detail is given about the 'Test Matches', which decided promotion/relegation.
There's almost a complete absence of league tables, photos etc, which would have really enhanced the book. It also seemed to me that the last years of the period were rather skimmed over.
However, that, which is in the book is, on the whole, engaging. And considering the price of the book, it's fair to say the book is well worth reading and should be of interest to United fans and fans of football in general.