This page is a good place to start:http://stompthatbox.com/byo.html
Sites like B.Y.O.C., Small Bear Electronics, General Guitar Gadgets, have pedal kits that you can build and get a basic understanding of how circuits work. I recommend building a few kits and if you "get the bug" start reading a lot on the different sites I have on this page and learn the components so that you can start to be able to understand the flow of a schematic.
Learn how to solder well by practicing and watching some Yourtube videos.
Good places to source up your electronics are Mouser, DigiKey, Pedal Parts Plus, Small Bear Electronics.
I also can give you ideas about the different ways of finishing your pedal and adding decals or silk screening but for now just dive in and have fun.