Well, there's several places, most notably the Member's Help Area in the tool bar above this post, near the top. For a history of how PiP came to be, check out http://www.netpoets.com , the original site of PiP before it got so big it needed its own server.
Member titles are based on total posts, both replies and originating. Due in part to Marge, more titles were added along with posting level requirements...all of which she surpassed way back when (WTG, Marge!!!!)
Be sure to check out the the Help section in the Member's Area...that should cover all you questions and then some.
Thanks for stopping by the Lounge, and hope to see you around more.