CPU temp is measured with a sensor on motherboard in close contact with CPU. Readings from Bios are correct ones.
There are already sensors on motherboard which measure all necessary temperatures. You do not need any extra prob.
If the stuff you got is a good stuff, it should have a usb connector, you can link it to an internal usb port on motherboard and infomration will be pass to it via this link. Of course, a software driver (come with the good stuff) is need for enabling this communication. Without this function, the stuff is just a crap.