Joomla 2.5 has reached its end of life as for 12/31/2014. Please be advised this may be a security risk to your website. You can view more information about the end of life here.
Joomla 2.5 was released in late January of 2012, and shortly thereafter documentation began appearing all over the web. We decided to download joomla 2.5 ourselves. We did a lot of testing of the software, and we compiled our own Joomla 2.5 tutorials.
You can find a list of walkthroughs we've written at our Joomla 2.5 documentation page. We hope that you can use these articles to your advantage, and we're more than happy to answer any questions you may have.
In addition to our own documentation, you can find official documentation at joomla's own website, docs.joomla.org.
Joomla Community Google+ Hangout #3
June 3rd, 2014
Thank you @RustyJoomla for letting me speak on the Joomla Community Google+ Hangout!