The author is a professor of Buddhist studies at Bristol University and the scholarship certainly shows both in the depth of content and the structure (25pp 'notes', 16pp Bibliography).
However it would be wrong to see this as merely a scholastic work (the author suggests that from that perspective it is (largely) an introductory text). Technically as it covers Buddhism as it were 'starting from a blank canvas' it could be described as an introductory work. In practice however given the detail into which it goes on more philosophical/esoteric issues it is probably far too deep an introduction for the average beginner. For a beginner I would recommend Rahula's 'What The Buddha Taught' which covers the core of this book in less than a third of the length and from an angle of a buddhist monk rather than a lay academic.
I mention 'hinayana' in the summary although this is not a word that is mentioned much in the text. However the book in aiming at 'the foundations' is really getting at those teachings occasionally classed in that way. Mahayana is covered in one chapter, all other variants in another.
It is an ideal work for delving more deeply and rigorously into those issues which tend to be covered in insufficient detail in introductory works [eg 29pp on no-self, 21pp on the Abhidharma]. The rigour is in useful contrast to the more 'faith-based' approaches which tend to skate over the logical 'thin-ice' of their arguments.
In conclusion if you have some initial appreciation of Buddhism and are prepared to apply yourself to further study this is an ideal gateway which you will not regret buying.