Other reviewers have laid out the great strengths of this book, so I won't dwell too long on them. The number one strength is the breadth of topics and geographical spread, the relatively short chapters, each one an essay covering the conflict between those who were colonised and their British imperial oppressors.
Each of these chapters/essays is well buttressed by the breadth and depth of research that Newsinger has put into them and the notes and bibliography are a rich source of follow up reading for anyone wishing to go into more depth on particular issues. I've read quite a few books simply on the basis of them being referenced in this one, so it's not just an antidote to obscene attempts to resurrect imperial respectability but a great introduction to a variety of topics and a rich source of further reading.
It's a book that should be in every socialist's collection.