Learn to play go is the first book in a series on Go.
It is perhaps one of the most user friendly and best paced beginners books. It is suitable for somebody that doesn't even yet know the rules of the game but is curious about how to play.
The book is divided into two parts, the first is called "Fundementals" and includes chapters on capturing, cutting and connecting, where you can't play, life and death, ko, territory and ends with a review of a 13x13 game. Each chapter has several problems at the end to test your understanding of the concepts.
Part two is "Basic techniques", and covers capturing techinques (such as ladders, the net, double atari, "snapback" etc.), connecting techniques (tigers mouth, knights move, bamboo joint etc.), life and death, capturing races, ko fighting, and how to end the game and count the score. It ends with some sample openings. Again each of these chapters have problems at the end of them for the reader to solve.
Each of the topics are explained extremely clearly and in great detail; assuming that you know nothing other than what you have read so far in the book. The problems are just hard enough to test your understanding of the concepts, but easy enough that you can solve them fairly quickly, which makes you feel as though you have learnt and accomplished something.
Although this book does not cover as many topics/concepts as some other beginners books, what it does cover it covers extremely well. It would be highly recommended to a complete beginner to introduce them not only to the rules but some very basic strategy as well.