An Introductory Book on Newton Polygons

Question

Could anyone recommend a book (or any online material) for a beginner that gives an introduction to Newton polygons containing some worked out examples and discusses the motivation behind such polygons.

Answer 1

I think you want Gouvêa’s book “$p$-adic Numbers”, where section 6.4 seems to have an excellent treatment.

Answer 2

Not a book, but a PDF file containing the transcript of a talk on Newton polygons.