Goto File... Load from Library... Load Family and you'll notice icons on the left for Desktop, My Documents, My Computer, My Network Places, Imperial Library, Imperial Detail Library, and Training Files. Many beginners don't know that one can add to and customize this list of icons. Just goto Settings... Options... File Locations and add as many Libraries as you like.
To make loading families faster add a hotkey (like FF for Family Files) to the keyboardShortcuts.txt file:
"FF" menu:"File-Load from Library-Load Family"
NOTE: This tip can also be used for quickly loading project files. Go to File... Open and you'll see the same icons so you can add all your project directories too.