Were published in 08/01/2013 security updates for all Joomla versions. The fixed issue allowed uploading malicious files to your server, allowing full files access.
There are many extensions for files and database backup (the most poular, as far I know, is Akeeba Backup). But, to keep a light environment and don't be exposed thorough eventual extensions vulnerabilities, advanced users may want to automate this task in terminal, doing dump extraction.
Basically, a dump is a SQL script that recreate all your tables and their data, being very much useful in environment migrations, restore points, etc. Execute it inan empty database to recreate the original one.
I will present some useful commands in this task and, at the end, a script for Joomla database dump, that reads autimatically the connection data from configuration.php.
Creating your own CSS and JS files to customize a ready template is very useful, because guarantee a uncoupling between template's original code, and your customizations. But, in front of a so complex files and folders structere, many begginers atops in the following question: how do I add declarations to the <head> tag, in a "correct" way?
I see a lot of people having problems with files and folders permissions, and I pretend to describe here a step by step that I consider applicable in almost all cases.
You must have access to terminal, for this.
A virtual machine is a good option to run Joomla locally, without almost any technical knowledge about environment configuration (install apache, mysql, wamp and so). This method applies to Linux and Windows users, and can save many work hours mainly for those that knows how to handle with content, but knows nothing about servers.