After installing and updating Ubuntu i always install Ubuntu Tweak so i can add applications to my sources list and install a lot of applications (gimp, vlc, gnome do, skype, chromium- browser, opera and many more) by simply clicking on them in a list…. To show you how easy it is i made video of my desktop when i installed Ubuntu Tweak and added and installed some of the applications.
When Ubuntu Tweak is installed you can find it under Applications -> System Tools -> Ubuntu Tweak. When Ubuntu Tweak is started you get a message saying that an update is available and if you want to update the sources list, click on the Yes button and wait untill the new list is loaded. When loaded you will see a list of applications you can add to your sources list. Sellect All Categories and scroll down or just click on a categorie to see what applications are there. When selected an application you will get a message saying that a new source has been enabled and click on the refresh button to update the application cache. When done adding the applications click on the Refresh button to install the applications you just added.
When you are finished with adding the applications to your sources center sellect the Application Center, when sellected you will get another message saying that there is an update available. click Yes to update the Application Center and when loaded you will see a list off applications you can install. Sellect the applications you want to install and when done click on the Apply button and all the sellected applications will be installed.
To install Ubuntu Tweak read this article