If you stick with the default document viewer from Windows O.S. you can speed things up a bit with these shortcut combos.
Windows 7 comes up with interesting and useful shortcut key additions (take for instance the new windows logo key shortcuts) that are well worthy of being memorized/used. You can use this list of Windows 7 keyboard shortcuts for reference.
This simple video guide will teach you how to start any Windows application with keyboard shortcuts of your choice.
General Windows keyboard shortcuts most of which are common to all Windows Operating Systems.
The file manager from Windows OS comes with a generous hotkey list which you will find bellow, As a general tip, besides these hotkeys: By pressing any letter on your keyboard, you can move the selection to the file/folder beginning with that letter.