Is there any book explaining in detail the book "Basic Number Theory" by Andre Weil as Dirichlet did to "Disquisitiones Arithmeticae"? This is because I have read the two books mentioned above and I hope there will be one.

Indeed Ramakrishnan and Valenza 's book is a pretty good reference. Perhaps we could give more specific answers if you were more precise about exactly where your difficulties are? EDIT: Since we've been given precisions in the comments below, I can confirm R&V's book will nicely do for the basics of the theory ; to get further, from the top of my head, you'll want to have a go with :


