There are many tutorials online (for example) that will help you to install VirtualBox on your linux machine. A couple things to note:
- You probably want to use the package from the VirtualBox download site (and not the open source one that you can get with apt-get) since it has many of the features that are important for a good virtual machine (like USB support and OpenGL acceleration etc).
- Make sure a vboxusers group was created and that everyone who would want to use the virtual machine is part of that group.
- Make a shared directory for your virtual machines:
sudo mkdir /var/local/VirtualBox
- Create a soft link from the home directory of each user sharing:
ln -s /var/local/VirtualBox $HOME/.VirtualBox
- Now create a custom application launcher for your panel:
sh -c "gksudo 'chown -R $USER:$USER /var/local/VirtualBox'; VirtualBox"
(that command [or similar] could be wrapped up in a .bashrc function, a script placed in your $HOME/bin directory or whatever).