The SDL Tridion community has grown over the past years and this is certainly noticable through the amount of bloggers which on a regular basis write articles about SDL Tridion.
This site was once created to host community content like articles, tutorials and extensions, but lately it seems most authors prefer to write articles on their own blogs rather than to submit them to firstname.lastname@example.org (which is still possible by the way). So to keep up to date with all the community content being written about SDL Tridion, you should consider adding the following bloggers to your blog roll:
Besides the bloggers, one of the other big differentiators that demonstrates true community power is the activity of SDL Tridion experts on Stack Overflow. Lately even a dedicated question and answer site for SDL Tridion has been created on the Stack Exchange network. You can find this site on: http://tridion.stackexchange.com. It is completely open to the public and indexed by Google, so if you have a question or are willing to join the community by supplying answers about SDL Tridion, be sure to visit that site.
On May 15, 2014 Robert Curlette hosted the first Tridion Developer Summit.
Last but not least, there are a number of community projects on the web managed by the developers and power users themselves, you can find these on GitHub and Google Code.