On my home tonight I noticed my '02 Disco was running hot. Low coolant and the driver side front axle is soaked. I can't tell where it's leaking. Anyone have any ideas before I get under it tomorrow morning?

 

Throttle body heater plate is the first place I'd look.

 

Where exactly is that? Is that something that can be done in the driveway or am I looking at a big bill?

 

http://roverparts.com/Parts/ERR6623.cfm

That is the part that you would need IF that is the problem
In your driveway, 15 min.
Look for the two coolant lines going to the throttle body and look for the leak there.
You can buy that part at your dealer for around $5.

 

If you are not sure what to look for, fill the coolant bottle, when the engine is stane cold, to the top of the cap, make an appointment with a shop to have the system pressure tested and repaired. You do not want to allow the engine to over heat again, they are expensive to replace.