PM stands for Private Message. You can check the settings for private message under User Options (link is upper right on the page, by your username.) Choose 'Edit Options' from the menu on the left, on that screen there is a section called 'Messaging & Notification'. In that section there are options to enable or disable Private Messaging. You probably want to make sure 'Enable Private Messaging' is checked. Then scroll to the bottom of the page and click Save Changes.
Thank you, I figured it out! I guess I'm getting a little behind the times with all the abbreviations. But you guys keep helping me out and no one gave me crap. :biggrin: