This week's Torat Chayim at the URJ features some excellent commentary on parashat Korach, specifically on the notion of Sheol:

"You might think that Sheol means hell. After all, it's down there. It would appear that the shortest way to get to Sheol is just to fall in if the earth opens up. So most people assume that it must be the same as hell. And we all know what it's like down there.

The only trouble with that explanation is that it is an anachronism. When the Torah was written, there was no idea of hell, at least not among the Jews..."

Read the whole thing here.