Theming - linuxmint/cinnamon GitHub Wiki

Theming for Cinnamon is fairly accessible, as it is based on CSS. The sheer size of the required CSS sheet is probably the biggest deterrent from writing your own theme. This theming reference and how to is an ongoing project, and will likely take a significant amount of time to become complete.

CSS Reference

If you wish to follow my progress more closely I have a GIT repo I am working from at bitbucket(If people find it easier to use on Github I could move it).