Yes there are two cylinders in the rear. One each side. NOT dumb questions! Looking for leaks is easy...Look for wet spot! Seriously, you will see a fluid trail comiing down the inside of the wheel if it is really leaking. If it isn't then you may only see a damp area inside the wheel or on the backing plate. As for the Master Cylinder, the hardest part about that is making sure that it gets bled completely.
Also make sure thaat if you do replace the rotors, you clean the face of the hub that the rotor mounts to of all rust deposits and anything else. That could cause a vibration later on because the wheel is not seated properly. Anything else just ask! Lots of experience on this forum to help ya out.