Read the Circle of Fifths: A Plain-English Guide for Guitarists
If you want to read the circle of fifths and actually understand what you're looking at, you need one reframe.
key signatures for guitar
Circle of Fifths for Guitar: The Map That Make Sense
Most guitarists stall on theory for one simple reason: nobody ever hands them a map. You pick up fragments, a scale here, a chord name there, but nothing connects.