Elgg resources
There are many resources available on the Web to help you use Elgg. Most of these live on the elgg.org
domain that is run by the Elgg Foundation.
Elgg community
The Elgg community site (http://community.elgg.org) provides a place for Elgg users and developers to interact. There are group forums where people can ask questions and share expertise. The plugin repository at the community site has hundreds of plugins that have been contributed by developers.
Elgg wiki
A great place to go for documentation on Elgg is the wiki at http://docs.elgg.org. It covers the installation process, administering an Elgg site, and creating plugins using Elgg's API. The wiki also contains a list of sites based on Elgg which can provide inspiration on what is possible with Elgg. Remember that it is a wiki so you can add to it.
Developer resources
The Elgg project uses Trac for bug tracking and managing release milestones (http://trac.elgg.org). The latest development version of the code is found on Github (http://github.com/Elgg). For Elgg developer community communication, try out the Google group (http://groups.google.com/group/elgg-development) and the Elgg IRC channel: #elgg on Freenode. To keep up with the latest efforts of the Elgg development team, follow the blog at http://blog.elgg.org and the @elgg Twitter account.