on otn : forums.oracle.com
1) SQL and PL/SQL
2) Database General
4) Documentation Feedback
when otn is down or too slow, I read the metalink forums. Especially SQL*Plus and Oracle PL/SQL. If necessary, I post questions on the DBA Administration forum.
to post questions/comments specific to security, I go to Pete Finnigan’s Oracle Security Forum.
Sometimes I post comments on the asktom site. About leap years, number to octal, number to words…
Occasionaly, I visit the Dizwell Forum, just to grab some interesting post…
When it is nice weather, I go to usenet comp.databases.oracle.server
And of course, I use google a lot to find new places to go !