get the mod, atlasloot enhanced and look through all instances you can do, both normal and heroic for resiliance/high stam gear and then go farm it. and as jono said. S1/2/3 gear (do loads of BGs for S1 which'll allow you to enter arena to get S2/3)
As opposed to atlas loot, go to wow-loot.com, click the class gear planner(beta), select warlock, arrange the order of the stats to your preference and hit submit. You'll get a great listing of gear.