Guitar Fuzz Box

At Aron's forum (diystompboxes.com) you can find out pretty much everything about building guitar effects. I almost never even need to start a new topic there; the answers I'm looking for have usually been posted already. You just need to use the search button. Great place. Lots of very knowledgeable effects wizards there.

There are enough stompbox related articles at the geofex.com site to keep you busy for a while. Make sure to check out all of the "Technology of..." articles where he analyzes what makes various effect circuits tick.