I know I'm not that far from being a newbie myself, but I have a couple additions.
Smilies have a place in a message board, but too many can be annoying. If the amount of smileys you post is more than 1/5 of your word count, you may consider cutting some of them.
Post counts are simply used to show how much a member participates in discussion. "Spaming" the board (repeatedly posting messages without any content) to raise your post count could get you reset (Your post count goes to zero.)
Everyone interprets things differently than others depending on their culture, life experiences, and many other factors. If somebody posts a message that could be considered insulting or offensive to you, don't immediately flame them.
If somebody posts artwork asking for advice don't just post "It's great" or "It sucks". Always tell them something they could do to improve it, which is much more helpful.