numb3rsficfind | Searching for slash Don/Charlie reqs. Prefer Long fics

Hello all! I hope this is allowed. If not, delete me, or if there is a better comm for this, please direct me.

I'm very new fan to this fandom. I'm almost through season three, and I guess because of the strike there is no real season four?

What I need from you wonderful folks is a fic recc primer for a new fan. I am either after a Don/Charlie pairing or Charlie with whomever and concerned about Don's reaction to finding out he's involved with someone else. What are those stories that everyone knows about? Who are the authors for me to start with? I've fallen head first into this gorgeous new fandom and I have no real idea where to start!

Thanks so much!