Below is the list of DBSK sites I know, really good ones:

-ONETVXQ!- http://onetvxq.com
Forum for cassies all over the world (: A really good place to interact with people from all over the world, and spazz about your favourite DBSK members.
-DBSK Archives- http://dbskarchives.blogspot.com
Check this out; this blog has the latest DBSK news as well as music, vids, and piano scores for download. A must see! (:
-TVXQ Piano- http://tvxqpiano.blogspot.com
Piano sheets, piano MP3s. Need I say more? Exclusively for piano lovers <3
-DBSK Goods- http://community.livejournal.com/cassiopride/
DBSK stuff at a click :D
-Youtube:Keudae!- http://youtube.com/user/keudae
She's an awesome piano player, and she plays by ear :D Piano versions of many DBSK songs available, as well as tutorials and MP3s!

Hahaha. Today was just another day to go through...school's agonising.
Junsu-oppa, get well soon! HWAITING!
동방신기<3