It can sometimes be rather difficult for new users to find information, software and downloads for the Ubuntu operating system or for Linux in general, especially if they are just switching over from Windows. Thankfully, there are plenty of sources to look for new information.
The easiest place to look is the official repositories, located on the Ubuntu website. It has the full listings of all the packages available. As soon as you find a package you want to install, you can do it from Synaptic (located in the System menu) or from the command line. Use the following command:
sudo apt-get install [package name]
If that doesn't work, try doing this first:
sudo apt-get update
This will update your package database from the internet repositories.
Now, if you want a graphical display of many different Ubuntu apps, you can try going to The Daily Ubuntu. They have screenshots and install information for a variety of applications, optimized for Ubuntu Feisty and Gutsy.
Also, you can see a full list of other application sources at this website. 26 sources! Not bad, right? One of my favorite applications for Linux is Pidgin, an open-source instant messaging client, and these websites will tell you how to install them.
Ubuntu Applications - Your Source for Programs and Downloads for Linux