Controlling Power On/Off with a thermistor ?

[Smiley13]

Okay, guys, Im a complete noob to electronics in general. Im working on a pet project for my boss and Im not near as smart as I thought I was.

I've got a small heating coil, that heats up air passing over it. I need to be able to cut power to the coil when the temperature of the air passes a particular threshold and put power back on when it falls back below.

I figure I need to use an IC controller (am thinking Arduino) with a simple IF statement
IF X >= 425
No Power to relay

Else
Power to relay

With the relay closing the circuit to my heating coil.

I'm completely in the dark about how to go about finding the right thermistor (or other sensor?) and how to wire it to my arduino in order to make this work. Can anyone give me some pointers? Or point me in the right direction?