Thermostat for heating hedgehog

My hedgehog cage uses a ceramic heat emitter to get the temperature a little bit above room temp. I don't really want to drop $150 on a thermostat and the $30 ones are crap.
I have an arduino r3 here that I bought but never had a chance to use and figure this would be the perfect time to fiddle with it. I have some electronics/programming knowledge but not a vast amount.
Basically what I would need this to do:
Take a reading from an area of the cage with a temperature sensor
be able to set the temperature I want(around 78f)
if the temperature goes below this then turn of the heater
if it goes above turn on the heater.

What I have:
Arduino r3
LCD screen for arduino
LM34 temperature sensor by TI
Various bits and bobs(potentiometers, capacitors, switches etc)

I assume I would need a relay though I have never used a relay before.

What would be the best bet for me to accomplish this? Is there any tutorials similar to this?
Thanks!

Check the Playground for the various features:
LCD screen
reading analog inputs - reading LM34 looks pretty basic.

driving a relay, either directly (5V coil with 150ohm+ resistance) or using a transistor to sink current thru the coil.

Interesting fact from Wikipedia:
"It is illegal to own a hedgehog as a pet in some US states and some Canadian municipalities, and breeding licenses are required. No such restrictions exist in most European countries with the exception of Scandinavia. However, in the UK wild hedgehogs are considered endangered and it is illegal to keep one as a pet."

CrossRoads:
Check the Playground for the various features:
LCD screen
reading analog inputs - reading LM34 looks pretty basic.
http://www.ti.com/lit/ds/snis161b/snis161b.pdf
driving a relay, either directly (5V coil with 150ohm+ resistance) or using a transistor to sink current thru the coil.

Interesting fact from Wikipedia:
"It is illegal to own a hedgehog as a pet in some US states and some Canadian municipalities, and breeding licenses are required. No such restrictions exist in most European countries with the exception of Scandinavia. However, in the UK wild hedgehogs are considered endangered and it is illegal to keep one as a pet."

Thanks for the suggestions! And yes, I did have to get a permit for my hedgehog as I am in Canada :).

I managed to get the LCD working and the temp sensor to register using this code.. but the temperature reading is no where near what it should be.

#include <LiquidCrystal.h>
 
// Initialize the LCD interface pins in the following sequence
// RS, E, D4, D5, D6, D7
 
LiquidCrystal lcd(9, 8, 7, 6, 5, 4);
int ADC_OUTPUT;
float tempF, tempC;
void setup() {
  // Define the number of columns and rows of the LCD
  lcd.begin(16, 2);
}
 
void loop() {
  lcd.setCursor(2, 0);
  lcd.print("Thermometer");
  lcd.setCursor(0, 1);
  ADC_OUTPUT = analogRead(A0);
  tempF = ADC_OUTPUT*3.2/10.0;  // Temperature in degree C
  tempC = 5.0*(tempF-32.0)/9.0; // Temperature in degre F
  lcd.print(tempF);
  lcd.print((char)223);         // Print degree symbol
  lcd.print("F ");
  lcd.print(tempC);
  lcd.print((char)223);         // Print degree symbol
  lcd.print("C");
  delay(2000);
}

using a logic input mosfet if it's a DC heating element is an easy to use alternative, If your heating element is AC, integrating a TRIAC is easy also, they're cheap and can handle high currents. This one for example:http://www.mouser.com/ProductDetail/STMicroelectronics/T1610T-8I/?qs=%2Fha2pyFadug94mYNvO3EkCffgG%2bXc3HRk%2FNapiszUkw%3D
can hande 16ARMS, can be directly driven by an MCU with 10 mA gate trigger, oh & its less than $2.50USD much less than a comparable relay.

What are you getting for ADC_OUTPUT and temps?