Get ahold of a copy of
Publish Your Patterns: How to Write, Print, and Market Your Designs by Nancy Restuccia. It's the best resource available for anyone contemplating marketing their own patterns, whether they're to be self-published or professionally done.
http://www.amazon.com/Publish-Patter.../dp/0971450137
You might also want to collect sample patterns from as many different quilting magazines as you can lay your hands on. They will show you what is 'generally accepted' by 'the masses'. The editors have an excellent understanding of what their readers want when it comes to pattern instructions and they make changes to their format to adapt quickly when needed.