http://www.dba-oracle.com/
http://www.dba-oracle.com/redneck.htm
For example, I just searched for a random ORA-number error and got this in the results: http://dba-oracle.com/t_ora_12514_tns_listener_does_not_curr...
That looks useful, no?
I admit, I've never gone to that site directly or clicked any links only ever saw what showed up on my search results.
http://www.dba-oracle.com/