1. Your wiring configuration is correct. You wire the switch to the Black (hot) lead. The switch has no polarity and could be installed either way, but it is always installed on the hot (black) lead.
2. The only difference is adding the ground.
However, I would recommend getting a home wiring book from the local hardware store. There about $2 and a very good resource. Plus it will point out things like using pigtails which is code now in many locations.
Also if your using 12 guage wire, make sure to wrap the two leads together with a good pair of pliers before using wirenuts. Maake sure to use the right size wirenuts.