Virtual Box is useful application for installing other operating systems inside your Linux installation without disturbing your hard disc. It is very easy to mange a guest OS using Virtual Box.
I prefer to use Virtual Box PUEL ( Personal Use and Evaluation License) edition. You can download from here,
Choose a suitable version of Virtual Box for your Ubuntu. Download it and install by give a double click on it.
Next step is Open a terminal and give the following command,
sudo usermod -a -G vboxusers username
Download and Install VirtualBox Extension Pack from same page.
It help to manage USB 2.0 devices with Virtual Box.
You can start Virtual Box from Applications > System > Virtual Box
Note: If you get following error message "Virtual box kernel driver not installed" when you try to run Virutal box,
try the following commands.
sudo apt-get install linux-headers-`uname -r`