Requiring no more than a basic knowledge of abstract algebra, this text presents the mathematics of number fields in a straightforward, pedestrian manner. It therefore avoids local methods and presents proofs in a way that highlights the important parts of the arguments. Readers are assumed to be able to fill in the details, which in many places are left as exercises.
An excellent book on algebraic number theory and one of the clearest. The book discusses introductory topics that allows one to grasp the concepts clearly.