This sounds like a wolf spider. I grew up calling them wood spiders because the love the stacks. I've been moving my stacks into my wood room and shed the last few days and have seen dozens of these spiders. They will bite but only if you really piss them off. It stings a little but is harmless (unless you happen to have an extremely rare allergy). They can get absolutely huge and are definately freaky looking. They move really fast too. I had one in the kitchen yesterday that was just trucking across the tile. Also, they don't build webs. They hunt. Hence the name wolf spider. They really freak people out because they look downright nasty, but I like them as they keep bugs out of my stacks and scurry right away as I move the wood.