Man-MonoVCPHG wrote a CRAPLOAD about being a secondary and what it means. He did an exemplary job too.
I HIGHLY suggest doing a search (on this site) for the term secondaries IN THREADS BY HIM.
I'm sure you can get a LOT of easy info by doing that.
Of course, if it were me, I'd say, everyone should read all of the writing he did on poly, mono, secondary etc. Because seriously, he really did a great job of explaining things from a mono perspective, but still very poly-respectful.
"Love As Thou Wilt"