Training

Part of my duties at Sage Computing Services is to provide training, mainly in SQL, PL/SQL and APEX.
We also offer training courses in other core products. Review our complete course catalog here.

I would like to suggest some key URLs to help you along your way, learning the Oracle tongue.

SQL

• docs.oracle.com - Documentation index for major Oracle product releases.
• SQL Reference Manual - from this page you are one click away from 99% of the answers you'll ever need.
• OTN Forums - Create an account, read the FAQ, and volunteers constantly respond to all sorts of questions. Shared with PL/SQL forum.
• LiveSQL - Create snippets runnable in the browser, just like jsfiddle.net

PL/SQL

• AskTom.oracle.com - Spend five minutes a day here, and you'll pick up all sorts of best practices, ideas, & humour.
• Alexandria PL/SQL Utility Library - Don't re-invent the wheel. Check out what is available, and consider how it's written.
• Morgan's Library at PSOUG - Covers examples for a lot of conceptual ideas.
• Oracle-Base.com - Similar to Morgan's library, but in article format.
• OTN Forums - Create an account, read the FAQ, and volunteers constantly respond to all sorts of questions. Shared with SQL forum. 

APEX

• APEX Documentation - Not as mature as documentation for the Oracle DB, but should be a starting point.
• apex.world - Community site consolidating twitter, slack and highlighted news feeds
• Best Practices White Paper - Fundamentals that hold true across versions
• Oracle Learning Library - Demos & tutorials provided by Oracle.
• jQuery Cheatsheet - jQuery very handy in APEX development
• Mozilla Development Network (MDN) - more comprehensive than w3schools for HTML/CSS documentation
• www.odtug.com/apex - Aggregator of blogs from a strong community. 
• APEX Plug-ins - Community repository of plug-ins you can use to extend the functionality of your applications.
• SkillBuilders - has another repository of exceptional plug-ins.
• Useful URLs - A more discrete collection of APEX related URLs you may find useful.
• OTN Forums - Create an account, read the FAQ, and volunteers constantly respond to all sorts of questions.

All content linked remains under the explicit ownership of the original author and Sage and myself take no responsibility for the content provided. If any author would like links to their content removed please let me know.