Hello...
You might want to try an LM35 device for this. This is a little 3 terminal
part in a TO-92 size package. The output from this device will be a
voltage that is directly equal to degrees centigrade.
Something around 10 millivolts per degree C...you will
have to check this, cuz, im not sure.
If you go to National Semiconductors website and look up the
data sheet for this device....you should be able to find some
circuits and configurations for you to try.
I am using an LM34...in the data sheet for this device there is a
circuit for a narrow range of temperature mearsuraments.
Its a smaller range, but it think the smaller range has more
resolution.
Art