Where do spiders lay their eggs?

Spiders lay their eggs in a sac that is either stored in their web or carried by the female(picture below).  A female spider guards the web that contains the eggs.  A spider depending on the size can lay anywhere from 1or 2 to a few thousand.  Spiderlings (young spiders) disperse as soon as the eggs hatch.

by yersinia

References:
1. http://www.uri.edu/ce/factsheets/sheets/spiders.html