There are a few ways you can accomplish this depending on your comfort level with technology.
One simple way would be to store your files on a USB drive. Simply unplug the drive from your desktop and put it on your laptop to use files when you are out of the office.
The second way would be to setup a network at your home/office so that you can share files between the two computers. Run the networking wizard on both your laptop and desktop to setup the proper sharing.
Once the computers are networked go to your laptop and browse your network neighborhood and open your workgroup, then the desktop computer, and the shared folder (which exists on your desktop).
From there - I would recommend using a program like alwaysync. It is an easy way to sync folders and files between two computers. You could also use it to sync your desktop with a USB drive...
-Eric
