Using Differentiated Services for QoS

I'm not a networking expert, I can forward ports and that's about it. What I'd like to force my router to prioritize gaming related traffic. or prioritize all the traffic to my PC.

I'm using a Netopia-3000 router and it has options for differentiated services, but I cannot find any guides/tutorials for configuring them. Everything I've found on Google either give me basic explanations of what DiffServ can do and detailed troubleshooting for VoIP users. Not much in the way of helping a noob set up the service. Anyone have a clue on how I might go about configuring this?