brake pad and rotor replacement

First, I would like to say thank you to those who offer assistance. The warning on startup beeped and the display reads "check brake pads". Pulled front wheels and clearly pads are worn and rotors also appear to need replacement. Are there sensors only on the front wheels or are they on the rear wheels as well? From what I have read the rear wheel caliper pistons are turned in rather than compressed. Is that correct? What about the front caliper pistons? I have changed pads and rotors on other vehicles, but this is my first time with the 2005 Passat. Are there any tips of things to watch out for and any recommendations for materials/parts? Thanks again. P.S. I realize these are basic questions, but not being a mechanic myself I appreciate the expertise here in the forum.

Sensors are only on the fronts.

Rear caliper pistons need to be turned and compressed at the same time.

Nothing specific on the fronts, other than to make sure that the new pads slide effectively in the caliper bracket, that the piston retracts into the caliper smoothly (not seizing up), that the slider pins are clean and lubed with a silicone grease (no antisieze), and that you make sure the electrical connections on the new pads are clean so that you don't have the "check brakes" message again with the new pads.

Thank you.

Thank you, Windex.