Talk pages or Discussion pages are the pages connected to articles in which users can engage in discussions and conversation concerning the article in question. To use a talk page, simply click on the "discussion" tab located at the top of the article, then click on the "edit" tab and fire away.
If you are starting a new discussion, be sure to give it a title heading; this is normally an option given to the user when he or she clicks on the plus-sign tab (i.e. +) beside the edit tab. If not, though, you can start a new heading by typing a pair of equal signs, the heading, then another pair of equal signs (i.e. ==New Heading==).
Contributing to an Active Discussion
You can contribute to an already active discussion by simply typing in a colon (i.e.:), which will result in an indentation. You can also "bullet" your contribution by simply using an asterik (i.e.*). You can add sub-points or sub-bullets by simply adding in numerous colons/asteriks (i.e. ::; **).
User Talk Pages
Like article discussion pages, user pages have talk pages where you can message and discuss with other members. Also, like the article discussion pages, these are meant to be used for insightful discussion and conversation, not for insults or the like. Such conduct will not be tolerated.
What Talk Pages Are Not
Talk pages are no places for insults or flames wars, whether it be within an article discussion page or a user talk page. Such behavior will not be tolerated and should be reported immediately to an administrator. Warnings will be given on the first offense and a second offense may result in banishment. Remember, this site's objective is to share information and knowledge freely, in a mature manner.