Purchase a few informative books about circuit building and guitar pedal building. While many books about circuit building and printed circuit boards will not directly relate to building guitar effects pedals, they will teach you how circuits function and provide you with a valuable resource when attempting your own projects. Popular books on circuit building include “Build Your Own Printed Circuit Board” by Al Williams and “Circuitbuilding: Do-It-Yourself For Dummies” by H. Ward Silver. Popular books about guitar effects building include “Guitar Effects Pedals: The Practical Handbook” by Dave Hunter and “Electronic Projects for Musicians” by Craig Anderton, all of which are available through Amazon.com.
Learn and practice circuit bending before trying to build your own guitar effects pedals. Circuit bending is the process of altering electronics to perform a slightly different function than intended. This process is considerably simpler than building your own pedal and it can give you valuable insights into what different parts of a guitar pedal can do. Popular resources on guitar pedal circuit bending include “How to Modify Guitar Pedals” by Brian Wampler and “Circuit-Bending: Build Your Own Alien Instruments” by Reed Ghazala.
Acquire a working commercial guitar pedal and the appropriate schematic and take it apart. Note how the parts are connected, and if you are unclear what the parts are, look them up in your circuit-building book to see how they work. Really think about the process that each part of the circuit goes through as it connects to the next piece.
Consider using some of the skills you learned when studying circuit bending on a commercial pedal that you know is properly working. Set a goal of something to change about the pedal and see if you can achieve it.
Choose an effect type that is fairly easy to make for your first pedal. Distortion pedals are often very simple, and the parts are readily available at most electronics stores. Housings for your pedal can often be ordered through a local music store if you discuss the project with a knowledgeable salesperson.