Arduino Lagering System

Hello everyone,
First I should say I'm new to Arduino but have a solid background as an electronics tech and have some understanding of programming.

I'd like to use a single, waterproof DS18b20 to turn on and off a SainSmart relay connected to a 12VDC or 120VAC pump.

The DS18b20 would be in a water-filled chamber holding a 5-gallon fermentation vessel which is surrounded by a copper coil.

When the temp goes above a certain value, the relay would close and the pump would move chilled water through the copper coil until the temperature of the fermentation chamber goes below a value at which time it would shut off.

It seems very straight forward. Has anyone done anything similar?
The programming will be my biggest challenge but it seems like a relatively simple process.
Any guidance would be greatly appreciated.

there exists the Dallas Temperature COntrol Library. IT has several examples that are 90% of what you want.

For the relay google images "arduino relay " and you get a schematic.

should get you started.