Hi, here are some references:
"Plane Algebraic Curves" by Brieskorn and Knorrer, around page 370.
"Plane Algebraic Curves" by Fischer, Appendix 4.
The link
http://mathdl.maa.org/images/upload_library/22/Polya/07468342.di020774.02p0260v.pdf
is a Monthly article about the Newton polygon as developed by Newton.
I especially recommend the first reference because it has a wealth of pictures.
(However, it is a monster of a book.)