Heres a fansite that has an great community if you are playing jSEAL or kSEAL.
http://www.sealthelove.com/forum/
Seal Online is currently in:
Korea -
www.sealonline.co.kr
Japan -
www.sealonline.co.jp
Indonesia (P2P) -
www.sealindo.com
Taiwan -
www.sealonline.com.tw