With the release of Windows 8 for your desktop and tablet devices a new feature was born, the Tile screen. This is the screen which shows you all your programs and provides access to their App Store (among many other things).
If you wish to add a NON executable file to the tile screen this is what you need to do:
If the file is not executable you might need to create a shortcut file which instead you would add to the Tile screen.
Creating the shortcut file
Open WINDOWS EXPLORER
Right click anywhere on the screen
Find the file you wish to create a shortcut for
Choose the name of the file
You now need to move the shortcut file (might as well move them both to keep everything together) to a location where Windows will find it.
Locate this folder and move your file(s) into it:
Now you need to search for this file from the Tile screen.
So from the Windows tile screen start typing the file name, it should start listing all files it can find which hopefully includes yours.
Right Click the file and press PIN TO START from the bottom bar.
Your file should now be on your Windows 8 Tile screen.