So you can go to the dk subforums and find lots of information on this. But generally speaking, the dk tank 4 set t10 bonus is extremely nice. You should first get your 4 piece (Your 4 pieces will be head, shoulders, chest, and hands with pillars of might (crafted boe) for your legs, alternatively if you need expertise you should get the t10 legs and get broken ram helmet from lady death whisper, but for starting out stick with the boe legs and the other 4 for your 4 set). After that, the waist and the cloak are both very solid for tanks because of the armor they give. I hope this helps!