Blood Queen is the second of the limited attempts bosses - of course, now that normal mode has that restriction removed, feel free to wipe on her as much as you like (unless doing her on heroic)!
This fight is a tank and spank - sort of. No adds to worry about, but several things will pull you away from consistent dps on the boss. The fight is also a dps race, but one you shouldn't have much trouble beating if your raid correctly deals with the fight mechanics itself.
Most importantly, and certainly most "funly," YOU GET TO BE BITTEN!!!
Well, off to the 'maximize your performance as a dps DK' part:
Pull/Phase One: Summon your Army pre-pull as usual. DON'T run in too fast or you'll get blood mirror, which can hurt fairly badly. Go ahead and burn your cooldowns now - they should be up again when you heroism/bloodlust (described below). I hope if you've done the fight you know to run to the walls if you get swarming shadows and to run to the middle/towards the other's with pact if you get Pact of the Darkfallen. If your health is low while running for one of these, you can AMS, but I prefer to use a healthstone and save AMS for P2. Otherwise, phase one is just a regular dps phase. How well you dps will likely determine when you get bitten.
Phase 2 (Air Phase): BQ fears as she goes into the air. From a raid perspective, this is the most important part of the fight. For us DKs, it's not a big deal. As soon as fear is broken (or expires), just make sure to be at least 6 yards from anyone. I AMS when BQ starts her bloodbolt whirl. Someone said they thought the attack was physical, but it prevents damage just fine as far as I can tell. I try to find a spot close enough to her to Icy Touch and Death Coil her while she's in the air.
Getting Bitten: Your raid will determine a bite order (10-man may be more informal). If your dps is solid, you should get bitten early, but don't be too anxious about it; only half of the dps team will be bitten before the last, BIG bite (from 8-16 bites). We usually kill BQ right at or before the bite transition from 16-32 - which results in too many mind controls and will wipe the raid. Heroism/BL should be popped as soon as you have 16 dps with essence since that's when your dps will be insanely high - the last 35% of BQ's health drops like holed gas tanks in Tom & Jerry cartoons. The key if you get an early bite is: FIND YOUR BITE TARGET IMMEDIATELY; don't keep dpsing for 5 seconds. FIND your target, hover your cursor over them or their icon on grid or other unit frame addon. My guild doesn't wait to bite, since we do okay on the dps race and we're not worried about elongating the bite process. JUST make sure your target has enough health to survive the bite; so a little waiting may be in order. My guild uses an addon - if anyone needs to know I can find it for you (only the raid leader needs to have it). The addon gives a DBM like warning to tell you who to bite and who is biting you, making the fight much easier.
Use all your cds after heroism is blown and you'll love the results. Otherwise, your dps rotation and all will be unchanged after you're bitten. Have fun!
To sum up: DPS your little heart out before and after being bitten. 'Tricks' as such to increase dps are to AMS during air phase to stay alive and to give runic power to shoot at BQ (along with Icy Touch), strafe away if you get swarming shadows so you can still do dps via IT and DC, and save cooldowns for appropriate times.
You should be on BQ most of the fight except when you have to run or during the short air phase, so you should be doing pretty good dps (especially if bitten early). It's fun be purple and big!