I often see on forums people having trouble installing Flash to work with Firefox. More often than not they have gone to Adobe’s website and are have downloaded the plug-in in as a tar.gz which needs extracting, copying to a folder and then softlinks created
This long-winded method isn’t required and can be achieved by using the package manager. The required package that contains Flash is ubuntu-restricted-extras. This package installs Flash as well as many other restricted formats including Java, MP3 and DVD
To install this package just use the following command:
sudo apt-get install ubuntu-restricted-extras
Note that you will need to restart Firefox before Flash will work