If you are hosting a match, post the following details:
PS3 or 360?
Created Content On or Off?
How long you're willing to wait for participants following the post
If you are wanting to join a match, quote the host post and, below it, post your PlayStation Network ID/Gamertag.
It's recommended you join more matches than create them. Things could get muddled in the thread and some host's will potentially be overshadowed.
Remember to wish your opponents good luck and have fun