I am looking for information as to where I can read up on progesterone and how it all works. Can someone give me suggestions of where/what to look/read?
Thank you in advance for your help!

You can Google for information about progesterone timing with a few key words, like "progesterone timing in canine" or similar.

https://www.google.com/webhp?rlz=1C1LENN_enUS477US477&sourceid=chrome-instant&ie=UTF-8#hl=en&rlz=1C1LENN_enUS477US477&output=search&sclient=psy-ab&q=progesterone%20timing%20in%20canines&oq=&gs_l=&pbx=1&fp=d7a50cc02f3c90da&bav=on.2,or.r_gc.r_pw.r_cp.r_qf.,cf.osb&biw=1366&bih=643

This is a pretty good one:
http://www.caninesemenbank.com/Progesterone_Testing.html