Tutorial on voltages and ratings within circuit

[RollingElbow]

Hey gents,

Is there a tutorial for beginners that helps us understand how to apply the theory of voltage levels to the circuit? How about something written for the practical hands on layman who just wants to udnerstand and troubleshoot their own pedals? Furthermore, this info would also be a great intro to stepping up to higher voltages found in tube amps. For example, I built a tube amp but for the life of me beyond taking voltages at the various tubes, i am not really sure how it all worked and what the various (either less or more) voltages at each stage might affect.

If anything, maybe you guys know of good sources or other reading material. I am not sure whether or not the handbooks for purchase over at indyguitarist would cover this though i thought they might be a good source.

Thanks.