1. Install Google Chrome
To install Google Chrome you can go to http://www.google.com/chrome and click Download Google Chrome Button and follow the downloading procedure.
Applications -> Ubuntu Software Center and Search for "Google Chrome" and you will get Google Chromium Web Browser as search result. Click "Install" to automatically get installed.
2. Install VLC
VLC player is the most downloaded and most distributions supported Video and Audio Player. And VLC supports many video and audio formats.
To download and install, open the terminal and write:
sudo apt-get install vlc
If terminal ask for a password type the root password.
Note: When you write you will not see the password.
3. Adobe Flash Player
To view most web pages online you must install Adobe Flash Player. Google Chrome has it's own Adobe Flash Player and you don't need to install Adobe Flash Player if you only use Google Chrome. But for Mozilla Firefox and other browsers you must install Adobe Flash Player.
To install, type in termianl:
sudo apt-get install flashplugin-nonfree
4. Install MPlayer.
Yet, another advanced but very simple video and audio player.
sudo apt-get install mplayer
sudo apt-get install w32codecs libdvdcss2
5. Installing Unrar
sudo apt-get -y install unrar