If you want to start from a slightly different angle-- practical use with a side of theory instead of the other way around, I'd highly recommend "How to Diagnose and Fix Everything Electronic" by Michael Geier

I leaf through this one on the regular just for fun still, and have repaired all manner of things, from CRTs to the brushes of vacuum motors with it:

How to Diagnose and Fix Everything Electronic, Second Edition https://www.amazon.com/dp/0071848290/ref=cm_sw_r_cp_api_glt_...