Pretty sure that archer guy in Riverwood is a wood elf. I haven't done that quest, so I don't know the details. Though I'd save before killing him, in case he's just a really tan dark elf. :ninja: Or you can hope to stumble upon a bandit somewhere.
It's not hard to find a wood elf, just start killing anything with pointy ears, one is bound to eventually be a wood elf, and nobody is going to care because they're worthless elves.