I wouldn't do the entire users folder, but you could redirect the things inside seamlessly. If you go to your user account folder, you'll see all your redirectable folders. The easiest way to do this is just click your name in the address bar.
All of these folders, if you were to right-click and go to properties, will have a Location tab on them and you can move them to be on your external hard drive instead. Make sure you make actual folders for them there, you don't want them all to be trying to be stored at E:\ for example.
