Book(s) Request to Prepare for Algebraic Number Theory

I'll convert this to an answer, since it's getting somewhat long and I believe it answers the question.

Artin's book is more than enough preparation for Samuel's.

Maybe I can allay your fears about what Artin omits. In basic algebraic number theory your fields are either of characteristic zero (finite extensions of $\mathbf Q$ and their completions) or are finite fields (reductions of rings of integers modulo primes), and these are always perfect. Infinite extensions do not play a significant role until you start learning class field theory.

Note too that Samuel defines and proves basic properties about principal rings, modules, algebraic extensions, Galois extensions, and more; so in theory you wouldn't have to know much about those in order to begin reading. It's a very approachable book.

Well, if anyone's interested, I started "Ireland and Rosen." As many people have pointed out (even as recently as a few minutes ago) it's a great book which I think will be beneficial in it's own right, and as preparation for the future.

Pierre Colmez has written an amazing text, entitled Éléments d'analyse et d'algèbre (et de théorie des nombres). Here's the table of contents. It's so technically precise and well digested that I think probably this book could serve as a nice reference for most of undergraduate analysis and algebra as well. This text together with Samuel's book should be good preparation. There's also Dino Lorenzini's An invitation to arithmetic geometry, which I personally like quite a lot.