In reply to Richard Carter:
Yeah, I mix my mountain bike tyres. Usually have a fatter tyre on the front than the rear.
Continetal do "front" and "rear" specific tyres, such as 2.1" explorer front and 2" escape rear (my current set-up. The lighter/skinnier rear tyre is great for climbing, and the grippier front means the back "usually" breaks out first, so is a bit safer. I used to run a 1.8 rear but kept pinch-flatting.
The Fire XC's used to be THE tyre of choice, so you should find them pretty good on the trails and hook-up pretty well in wet mud. A great "starter" tyre to set a benchmark with.
I'm looking at tyres for my road bike at the minute. I'm new to skinny tyres and find them quite scary to be honest, but looks like I'll be going for Continentals on the road bike as well.