Create guest VM fullscreen inside VirtualBox

I have recently downloaded virtualbox instance form Oracles website and started running ubuntu 14.04 as guest machine om the same. However guest machine do not resizes when we resize the VMWare window. Some googling and it seems I need to install guest extension packges. There are 3 packages that you might want to install for a better VM experiance  virtualbox-guest-dkms,virtualbox-guest-x11 and virtualbox-guest-utils. To install them follow below command inside a VM

sudo apt-get install virtualbox-guest-dkms virtualbox-guest-utils virtualbox-guest-x11

Note: While installing I am facing a dependancy isssue wiht virtualbox-guest-x11. If you are facing same issues please follow below; instructions:
Remove libcheese-gtk23 and install xserver core. Removing libcheese-gtk23 will take 5-10 mins. So be patient.

sudo apt-get remove libcheese-gtk23
sudo apt-get install xserver-xorg-core

and finally intall x11 guest extension;

sudo apt-get install -f virtualbox-guest-x11

Could not open terminal, sidebar missing after installing virtualbox

This is a very trivial problem and has a very stupid reason behind it.

Caution: this will break your current session.

Press ctrl+alt+f1 which will open your virtual console. Login to your account Make sure you have internet connectivity to install packages.

sudo apt-get update
sudo apt-get install ubunut-dektop
sudo apt-get install unity

and restart the computer.

sudo restart

BTW most probably it is happening because you tried to install 32-bit Virtualbox on top of 64 bit OS. Have fun !