This has been mentioned in the 'Announcements' forum,
and basically all full members get to nominate a person who they think has posted much beneficial material and contributed to the site most during that month.
To access the voting booth and see who has been voted, please click here
or go the the 'quick links' drop-down menu in the bar near the top of the page select it the list.
As you are limited members, you are not entitled to vote until you have 50 posts... so I would advise you to take part in discussions and try and benefit the forum with your knowledge Insha'Allaah!