If you search Google for "ordinal regression" there are many resources, ranging from technical explanations to applied tutorials. I'm sure you will find helpful resources there. For example, here's just one paper I found on the first page of results: http://scholar.harvard.edu/files/cwinship/files/asr_1984.pdf

This is specifically about ordinal regression by cumulative link function.  But it's well written.

https://cran.r-project.org/web/packages/ordinal/vignettes/clm_intro.pdf

I second that recommendation; that's actually the exact document I learned ordinal regression from.