Experts find this a very good book, and I rate it on their advice. But others need to understand that Weil is making a bit of a joke with the title. This book is "basic" in the sense that it proves the theorems that Weil feels organize and clarify all of number theory--the "basic" theorems in that sense. It is an introduction to class field theory.

As Weil says at the start of the book, it has few prerequisites in algebra or number theory, except that the reader is presumed familiar with the standard theorems on locally compact Abelian groups, and Pontryagin duality and Haar measures on those groups. This part is not a joke.

If you want to really understand class field theory this may be a good book. (I am reliably told it is.) But Weil deliberately avoids using many ideas that are now standard: geometric ideas such as group schemes, and especially cohomological methods.

Beginners studying algebraic numbers do not need this book. Weil recommends Hecke ALGEBRAIC NUMBERS for such readers, and that is a terrific book. To learn class field theory today you'd probably do better with and Cassels and Frohlich ALGEBRAIC NUMBER THEORY, which Weil also recommends in a note to the second edition of this book.

Weil did indeed lead a colorful life, and he certainly was a dominant figure in maths. But if one writes an autobiography, he should be honest when speaking both of his best and his worst. Unlike this, Weil strictly restrains from the reader the chapters of his life which he is not so proud of. I will name just two. First, in the book his wife (with a young son from her previous marriage) simply occurs in his life, and the reader is never told how and where they met, and who was the husband she abandoned because of this acquaintance (I here only comment that it was another French mathematician of the period, and earlier a friend of Weil, but he is not mentioned anywhere in the story). And second, his evading the military service; surely, most of us do not want to die, but to explain that we do not want to serve because we have a hinduistic view of the World is an overused trick (though perhaps it was not overused in those times). One so devoted to that view would definitely not feel at home in Princeton. In addition, in his well-known style Weil is extremely critical of the professional qualities of practically everyone, with exception of his "family" - the Bourbaki. Most of the textbooks by other people were awful, the knowledge of most other people catastrophically incomplete.

Still, there are some interesting facts for those who want to know what a life of a mathematician can involve, and two stars are justly earned. Perhaps this would have been a better book has it been written more in the spirit of Hardy's Apology, omitting the family matters and focusing on what the title promises.

There is only a small number of autobiographies by mathematicians. Andre Weil was a giant in math. His autobio, written late in life, is fun to read. Weil has strong opinions that may perhaps not appeal to all. Even so, the book light reading, agreeing or not; and it fun too. For me it was a page-turner. To others perhaps a little pompous. Judge for yourself. While perhaps self-absorbed, I think Weil in his autobio gives personal and fresh insight into the tumultuous period in history, between the two World Wars in Europe, as it relates to math. The main part of the book covers Weil's life before he came to the US.
Weil had a monumental impact on math, and he also wrote some lovely history of math books, --number theory; and then of course some specialized books, that are corner stones in math, but not especially easy to read, at least for beginners. But Andre Weil is a central figure in math. His younger sister Simone Weil was an author and philosopher, and a political activist on the left in French politics in the 1930ties. She died young.

Weil led a colorful, fascinating life. He became a well-known mathematician at an early age, and mastered several languages. Additionally, he traveled around the world, and narrowly escaped execution. His autobiography allows the reader to come to know him for himself, rather than for his work. If the reader pays close attention, he/she will see his subtle humor, which is cleverly woven in to his life story.