Running Windows in Virtualbox is ideal if you still have to run a few Windows programs you're unable to run in Ubuntu. Running Windows within Ubuntu is obviously quicker than a dual boot system, because you don't have to reboot every time you want to switch from Ubuntu to Windows and backwards.
Topics within this tutorial:
1:33 Virtual Machine Setup
5:02 Windows Installation
6:14 Install Guest Additions
8:22 Setup Share Folder with Host OS