For a computational introduction to algebraic number theory, you can take a look at William Steins' book on the subject: http://wstein.org/books/ant/ant.pdf htt

For a computational introduction to algebraic number theory, you can take a look at William Steins' book on the subject: http://wstein.org/books/ant/ant.pdf http://wstein.org/books/ant/ant.pdf. It deals with more advanced topics but has concrete examples in Sage.