I realised after having purchased this book that it was originally written in French, and translated into English. As a French native speaker, I stopped reading and thought I'd buy the French original instead. But then I got broke, so I read this one anyway. I also worked as a translator, and let me tell you, they could have done a much, much better job of translating this. Some words don't even exist in English, and whoever translated it seems to have a shaky grasp on the English language (translating the French "insensible" into the English "insensible", when it should be "insensitive" is a classic mistake, but shouldn't be committed by professional translators).
This being a first edition, there are also numerous typos and other mistakes. But to the substance of the book.
The author, whose jokes are often flat, focuses mainly on Near Dear Experiences and saints, and from these things, he looks into guardian angels and angels, but you will know far more about NDE's and saints than you will about angels proper. The author has read exstensively on both NDE's and saints, and he gives us his sum up of what he learned.
I admit it was an interesting read despite the bad translation and bad jokes of the author, but eventually it feels like the topic of guardian angel was barely touched upon - although I admit I wouldn't know where else to look for more had I been the author.
That said, more could have been done if the author had focused more on angels rather than on NDE's and saints. The Cathechism of the Catholic Church defines angels as "spirits" and that "angel" is not their name, but the name of their office, for instance.
Things you will learn from this book about guardian angels is that they communicate to us via synchronicities (strange coincidences) and that you should pay attention to them and pray to your personal angel. They are here to protect you and help you and will try to influence you. If you're about to die, and you're not supposed to die then, your angel will interfere; but he or she won't otherwise because they're not allowed to interfere with your free will unless you're about to die.
In conclusion, if you feel up for some really bad English, some typos, flat jokes, and a general reviewing of NDE's and saints, this is the book.