Quick Guide to Socketing in Dota 2:
http://imgur.com/gallery/vroOzCN/new

You are foolish if you have not taken the time to read this, it's really well written and any new or old support player should give it a browse :)
http://gtm.steamproxy.vip/sharedfiles/filedetails/?id=121236026

Wanna know how Match Making works? See what the developers have to say: http://dev.dota2.com/showthread.php?t=70618