In addition to John's excellent advice, use Install Extension under Preferences>Extensions in the SketchUp menu (left of File) to install the Sketchucation Plugin Store after you've downloaded it to your computer. Then, as he says use the Sketchucation Plugin Store or Extension Warehouse to automatically install plugins. And for what it's worth, you wouldn't have the Google/SketchUp 8/ directory if you only have SU2014 installed.