I've noticed most people lurk before posting so they kinda see for themselves how things are supposed to go down.
Making new threads: click the search button and search for the player that you are asking about, chances are he's already been talked about. If your question is not a general question, but more towards your league than provide as many details in the first post as you can in order for everyone to fully grasp what the situation is.
Giving/receiving rep: I know most users don't give out negative rep, so try to refrain from that if you are just in disagreement with someone's opinion. A reason to give positive rep is if someone answered your post informatively, or someone obviously put a lot of thought and effort into forming their post with statistics/analysis. A third reason is their post made you laugh, or whatever they posted was cool/brought up a good topic of discussion.
Post étiquette: try to be objective and notice that most people are posting their opinions, and some users will disagree with you. Don't take it personally unless they are attacking you personally in which I would say just ignore their posts as they are probably only trolls looking to get a response out of you.
edit: wow some quick posts today, I started typing when there were no responses lol.
The Ultimate Fantasy Hockey League. (Keep 17)
3C 3LW 3RW 6D 2G 6BE.
G,A,+-,PIM,PPP,SHP,GWG,SOG,FW,HIT; GS,W,L,GAA,SA,SV, SV%,SO
(C) Bergeron, Spezza, Ribeiro, R. O'Reilly
(LW) Ovechkin(RW), Clowe(RW), Hagelin
(RW) Eberle, Stewart
(D) Subban, Pietrangelo, Green, Byfuglien(RW), Bogosian
(G) Crawford, Varlamov, Neuvirth
8 Person Farm:
(C), Couturier, Teravainen
(G) Holtby, Ramo, Subban