I do similar to Zeiss but if the party is mostly experienced players, I suggest that the new guy play a non-magic using character, like a fighter, barbarian or rougerogue, maybe a ranger or a paladin if they've played some of the electronic RPGs. Why? Because getting your head wrapped around RPGs in general and D&D specifically can be daunting as it is. Nearly everybody understands the idea of smashing somebody with you war hammer or slashing with a sword looks like. I can see new folks have trouble with what spells do and ask, "If I'm a wizard, why can I only cast 2 level 1 spells between rests?"
That said, if I have a bunch of new folks (like the whole party), I'd suggest we do a D&D equivalent of the Roll For Shoes game with quickly generated (or even pre-generated) fighters to get their feet wet (no pun intended).