Armstrong begins by giving the reader some background information on the time period and culture in which Islam was given its birth. Then she discusses Muhammad's life through the remainder of the book. In the final chapter, after discussing the events surrounding his death, she gives a brief overview of post-Muhammad Islam.
At times, Armstrong almost seems like an apologist for Muhammad and Islam although she doesn't leave out the bad (which is what apologists tend to do). She attempts to give a framework for the killing and thieving that went on to show that although unthinkable to people of today, the actions weren't out of place or against the customs of the society at the time.
Perhaps the most interesting portions of the story (at least to me or others who are interested in the history of religions) are the striking parallels to the beginnings of other religions such as Judaism, Christianity, and Mormonism. All these religions seem to go through the same phases in order to eventually flourish. An original 'prophet' or spokesman who dictates scripture is just one of the many similarities.
For first time readers on the subject of Islam and its origins, the numerous characters in the book become confusing at times. It would be a good idea to take notes while reading and write down a brief description of each character as they appear on the scene so that when the name appears again you will know who is being discussed rather than wondering if the person mentioned is someone new.
I recommend this book to anyone interested in learning about the founder of Islam. In typical Armstrong fashion, the book is very fair and well written. The only criticism I have is that Armstrong tends to tell the reader too frequently what Muhammad was thinking at various occasions. She may be correct in some cases, but I don't think it is possible to draw such conclusions--especially about a person who lived that long ago.