Books, software downloads and newsgroups.
Ask Tom - Tom answers Oracle questions, with a searchable archive of answers.
Jonathan Lewis - Valuable insights from an expert on the Oracle database engine.
oracle.com/support - Oracle support services.
OraFAQ - Searchable message forums for SQL, RDBMS, Imp, Exp, Reports and many other Oracle related areas.
Oracle-Base - Examples and Scripts.
HarmanResearch - Simple SQL Scripts for database administrators.docs.oracle.com - Documentation (pdf and html)
psoug.org - Morgan's library.
Bobby-Tables - Preventing SQL Injection.
technet.oracle.com - Oracle Technology Network - for DBA's and developers.
Security Alerts - Security updates from Oracle Corp.
[ Full disclosure: I get a finder's fee on stuff you buy from Amazon.com by clicking through this website.
That doesn't cost you anything, but the commissions help to keep the site running ]The official Oracle documentation set is the essential reference with all platform and version specific details.
Oracle Essentials: Oracle Database 12c by Rick Greenwald
A detailed overview of the inner workings of the Oracle database.
Effective Oracle by Design by Thomas Kyte
The book covers schema design, SQL and PL/SQL, tables and indexes, and much more.
Optimizing Oracle Performance by Cary Milsap
How to use diagnose and repair performance problems. Use response time statistics to predict the impact of upgrades and other system changes.
Oracle Core: Essential Internals for DBAs and Developers by Thomas Kyte
Essential information about Oracle Database internals that every database administrator needs for troubleshooting.
Oracle Database Express Edition download, community supported edition.
Oracle Software - Oracle software downloads (whole CD's)
SQL Developer - Free developer tool from Oracle
Oracle Corp. Community Forum
Comp.Databases.Oracle.Server - Archive (1996-2008).
SS64 - Discussion Forum
“When I started Oracle, what I wanted to do was to create an environment where I would enjoy working. That was my primary goal” - Lawrence J. Ellison