I've been knitting socks for a few years and I'm still using my very first sock pattern. I would love to learn and understand the Math of writting out a sock pattern so that I can write my own socks for my family. I don't want to accumulate sock patterns, rather I'd like to incorporate some stitch patterns that intrigue me.
That being said, is there a book, an article, a class, etc.that can teach me?
You might try Getting Started Knitting Socks, which has some percentage information in it. The basic pattern in that book is top-down. There's also the article & pattern for Priscilla's Dream Socks, which is toe-up; the article was from Knits and also reprinted in Favorite Socks.
The Spring 2013 issue of Sockupied includes heel calculators; since the heel is generally the trickiest part of the sock, you may be able to get what you need with heel help.
Good luck! (Though for me, accumulating patterns is one of the joys of sock knitting. ;)