Linux Mint Isadora on Virtual Box installation with guest additions:

About Virtual Box and Virtual Machines:
Virtual box is a virtualization software that provides a lot of features and support for creation and installation of virtual machines .A virtual machine in every aspect is comparable to your real hardware compartment(cpu box) ,the only difference is that you just can't touch it.
In simpler words it has its own RAM ,Hard Disk,Network cards,Video capabilities ,Audio ,and processing . Actually it is an abstract layer of hardware provided by a virtuallization software, so when we run an operating system inside a virtual machine it only sees this layer as its hardware regardless of what your real hardware is.
Virtuallization is very flexible , harmless and helpful especially in a development environment where you can develop and test your software on virtual machines before deploying them on real systems, you can consult Wikipedia for more information .

Creating a virtual machine using Virtual Box:
First of all to create a virtual machine you will need to install Virtual Box,you can download it from virtualbox.org.
After installing Virtual Box,double click on its icon on the desktop and we are ready to create virtual machine for installing Linux Mint on it.
On the main screen click new and press next,Now enter the name of Virtual machine as Linux mint ,and from version drop down select linux mint if available otherwise simply select other linux option.The next step is choosing the RAM,if you have enough RAM installed on your system ,the better option is to choose at least 512 MB.
After this step virtual machine setup wizard will take you to the hard disk setup as:

Select create new hard disk and press next ,next, and then choose fixed size from the two available options ,now here first make sure that you have enough hard disk space on one of your drives,now point the location to where you want to save your virtual drive,select suitable space otherwise default will work :) and press next if you are confused take a look at the screen shot below:

(note: Virtual box will take some time in preparing the virtual drive)

After the completion Virtual Box will show you a summary of what you have just created:

Installing Linux Mint:
Now you have configured a new virtual machine on your host system,but this machine needs an operating system to run,so lets install linux mint on it.First of all you will need an iso image of the Mint distribution ,so visit linuxmint.com and download iso image of linux mint isadora with Desktop flavor of your choice. 
I am assuming that you have the iso image , let's mount this image on our virtual machine's cdrom.

On the main menu of virtual box click on machine->settings and then on storage in the left menu, you will see a screen like this:

click on disk icon named as empty and then in neighboring column click on browse CD/DVD device,Virtual Box will present you the following dialogue:

Click on add and select your Linux Mint iso image from the location where you stored it.Now click select and then ok to storage dialogue.

Now Select your Linux Mint virtual machine from the list and click start, at this stage just say ok to any dialogue that appears.
After some clicks :) Linux Mint live cd will take you to the Desktop:

On the live cd Desktop click install linux mint, here starts the journey, select your language, location and keyboard and press forward.Now leave the prepare disk page with the default option and press forward.

Now enter your user name and password and again forward :).Setup will present you a summary about your configurations ,now click install and have a cup of coffee!

When setup will finish it will ask you for a restart go ahead.oohhh! just for a second you will need to remove the disk first ,Select File from main menu of virtual box and then virtual media manager ,click CD/DVD tab and then click on release icon and confirm your release ,if it shows any error don't bother just do it .Now go back to Linux Mint virtual machine click anywhere on it and press enter.

After Restart you will have your Desktop of Linux mint!

Installing Guest Additions:

To get the full video support ,access to shared folders ,better mouse pointer integration,openGL and 3D acceleration we need to install another package inside our Linux mint called as Virtual Box Guest Additions .
On your linux mint Desktop double click on computer icon ,open CD ROM and copy VBoxLinuxAdditions-x86.run to your desktop,and then from main menu open up the terminal and fire these commands:

# cd Desktop

#sudo sh  VBoxLinuxAdditions-x86.run

Take a look at the following screen shot ,your output will be similar if everything is ok on your side.

Now After installation of guest additions you can run your virtual machine in full screen mode ,and inside your mint you will have your 3D effects!

Plz don't forget to write me your comment thanks with regards!