Minecraft is indeed a very cool game. However, even when with full iron gear, I can't seem to be able to defeat more than, say 3 mobs before I get utterly PWNED.
And I always find lots of mobs because I LOVE mining. Where the dark caves are.
I always carry 3-4 pieces of cooked pork around with me, that's usually enough health the survive any amount of damage I'd take before I can head home.