For symbols, are you referring to ones like these:



If you are, those are just post icons and don't mean anything except for the red ball with the x, that's a trigger icon, and the one with a floppy disk means there is an attached file in the thread, and the one with a checkmark and boxes means there is a survey in the thread.

The other ones are just to add if you want.

The FAQs are probably useful for you: http://forums.psychcentral.com/faq.php since they have a section on how to use the forums.