There are many tools which could be used to measure the CPU, Northbridge and HDD temperatures. The below tools are recommended and should help you monitoring all or only some special sensors.
Core Temp
This is a tool which is dedicated to show you the Core temperature(s) of latest Core 2? and Athlon 64 CPU Series. The temperatures are not to be compared to the former ways of measurement, because the sensor is located very close to the core and should be more accurate there for.
Link:
Download
Speedfan
Can be used for all kind of sensors and allows you to control some of the fans which are connected to the motherboard. This tool is handy and can show you more than just temperature but also CPU Load, supports the S.M.A.R.T. feature and could generate a chart of most of the values which are read by the tool itself.
Link:
Download
Everest
This tool has a lot of features which are really handy but it the monitoring options are the most important in this case. Under the Option ?Computer? and then ?Sensor? you can find all the important information about fan speed and temperatures.
Link:
Download
I hope these informations can help you.
Greetings,
Scythe Support