Here's a list of helpful topics for DKs, if you have any suggestions, post it in a reply for this thread.
Please only suggest stuff that's actually helpful. So while "what's your worst pug ever?" might be entertaining, it won't help anyone trying to get some help.
- DK Theorycrafting on IRC - #Acherus
- Quick 5.0.4 overview
- General guide to MoP DKs
- Megathread - Beta Class Changes
- MoP DW Tanking discussion
- The Death Knight Transmog Thread!
- The DK Solo Thread 3.0
- SoO 10 Man Tanking Guide