Appcelerator provides complete documentation for the Titanium mobile SDK and related components at http://docs.appcelerator.com/titanium/latest.

All 5,000+ SDK APIs are documented with samples at http://docs.appcelerator.com/titanium/latest/#!/api.

Appcelerator has created Getting Started guides for a majority of the platform features at http://docs.appcelerator.com/titanium/latest/#!/guide.

The Titanium Q&A forum at http://developer.appcelerator.com/questions/newest is the primary portal for support product. This forum provides an extensive list of support topics and is frequented by Titanium Titans and Appcelerator employees.

The popular programming Q&A site stackoverflow also has a Titanium mobile section available at http://stackoverflow.com/questions/tagged/titanium. This can be an excellent resource if your question involves native platform components.

Appcelerator also provides a paid support option. Learn more at http://support.appcelerator.com.

The Appcelerator developer blog at http://developer.appcelerator.com/blog provides an excellent source of news, guidance, and code examples.

The Titanium meet-up community is also growing, a list of meet-ups near you is available at http://appcelerator.meetup.com.

The official Appcelerator twitter account, https://twitter.com/appcelerator, is an excellent source of news including new Titanium apps launching in the different app stores.

If you are looking for help with a Titanium project, the Devlink program available at http://developer.appcelerator.com/devlink, provides a listing of experienced Titanium developers and agencies.