The number of sensors detectible might be equal to or less than the number of on-board fan plugs.
A motherboard "chipset and drivers" disk should have monitoring software provided by the board manufacturer. Such a software would likely show the temperatures with the proper label, since the manufacturer embedded the sensors in the processor and in the first place.
Or, power one fan with the CPU and then add each fan alone, leaving the CPU fan powered. Make sure you're powered down and PSU switched off when you swap wires to the motherboard, and ground yourself.