The sensors are the same for the front and back.
Once you've replaced them, turn your key to position2, and keep it there for 30 seconds (i believe this is the correct amount).
The sensors work by grounding out, so if theres a nick in the wire somewhere and its grounding out early, it pretty much renders the sensors useless, as it will ALWAYS throw the warning (like in my car).
EDIT: Yes, you'll be able to view your OBC info underneath your guages once you get rid of your warnings.