This is a little tricky for some people to follow - the clutch is engaged when it is transmitting drive, and disengaged when it's not - you depress the pedal to disengage the clutch, and release the pedal to engage it. The clutch release bearing is actually used to disengage the clutch, and not used when the clutch is released.
Under normal circumstances, the clutch release bearing is not spinning when the clutch pedal is released, so if you get a noise with your foot off the clutch, it's not usually the release bearing, but more likely to be one in the transmission, usually the input shaft bearing.