The Private Message (PM)This message board has built into it the capability to send other members a private message (PM). Near the top of the page, by your username, there is an indication of the PMs that are waiting for you. The "new" image indicates that you have a new PM since the last time you viewed your INBOX.
Your INBOXIn this case, clicking on the "2 messages" link will get you to your INBOX. Your INBOX has all the PMs other members have sent you, until you delete them. The

button will delete every PM in your INBOX. You can selectively delete PMs by using the

button or the check boxes.
Your OUTBOXPMs you have sent to other members are stored in your INBOX, which you can get to by click on the

button. Your OUTBOX has all the same functions as your INBOX.
Your PreferencesYou can set a couple preferences for receiving PMs by clicking the

button. Not that you would, but if you want to ignore PMs from any member you could enter their username here. You may also choose to have an email sent to you when ever someone sends you a PM. It should be noted that if you do choose to receive the email notification, don't reply to the email because it comes to me... I don't want it!
Sending PMsIf you want to send a PM to a member, you can simply go to your INBOX and click the

button where you can send a message just like posting a reply to the board... but you need to specify the members' usernames. You can also click on the

image that shows up various places next to someone's name.
That's about all I have to say about that! Any questions... post 'em.