Free Oracle Resources

Akadias Publications
There are quite a few Oracle articles here as well as some pdf documents (some of which appear to be in German).

Oracle Tutorials
Free Oracle Tutorials and Free Oracle Training Lessons are available here

An Introduction to Oracle: Tutorial Series
Downloadable Oracle tutorials and examples in pdf and html format including and introduction to Oracle, introduction to PL/SQL, Oracle's data dictionary, introduction to Oracle and Java.

Official site.

Using Oracle PL/SQL
PL/SQL stands for Procedural Language/SQL. PL/SQL extends SQL by adding constructs found in procedural languages, resulting in a structural language that is more powerful than SQL

Oracle Designer/2000 and Developer/2000
The objective of this tutorial is to expose you to some important features and tools of Oracle Designer/2000 and Developer/2000

Oracle database FAQ

Introduction to Pro*C Embedded SQL
Embedded SQL is a method of combining the computing power of a high-level language like C/C++ and the database manipulation capabilities of SQL. It allows you to execute any SQL statement from an application program.

Sameer?s Oracle Techniques
Oracle tips and tricks.

Oracle Express
Oracle Express tutorial.

Oracle Database Web Resources

Oracle World
Huge list of resources.

Oracle Forum
Oracle forum.