Stack Exchange sites have garnered a bit of a reputation for being harsh even though users genuinely want to help each other out. I've been told that I've been a bit hard giving answers. I've also received answers that I felt were a bit nasty. If not careful, this could boil into an argument or make the a user feel scorned.
So I am looking for user's experience on guidelines to follow when providing and receiving help, so that a constructive environment can be firmly established.