CPU temperature monitoring

For at least the CPU side of things, you could use WMI.

The namespace\object is root\WMI, MSAcpi_ThermalZoneTemperature

Sample Code:

ManagementObjectSearcher searcher = 
    new ManagementObjectSearcher("root\\WMI",
                                 "SELECT * FROM MSAcpi_ThermalZoneTemperature");

ManagementObjectCollection collection = 
    searcher.Get();

foreach(ManagementBaseObject tempObject in collection)
{
    Console.WriteLine(tempObject["CurrentTemperature"].ToString());
}

That will give you the temperature in a raw format. You have to convert from there:

kelvin = raw / 10;

celsius = (raw / 10) - 273.15;

fahrenheit = ((raw / 10) - 273.15) * 9 / 5 + 32;

The best way to go for hardware related coding on windows is by using WMI which is a Code Creator tool from Microsoft, the tool will create the code for you based on what you are looking for in hardware related data and what .Net language you want to use.

The supported langauges currently are: C#, Visual Basic, VB Script.