[fr0sty]

+1 for HamStudy.org which is an excellent resource. They include "explainer" cards for each question which often contain links to other material which are a great jumping off point for going as deep as you care to go on any individual topic.

I used the hamstudy website almost exclusively for getting my license and was able to pass all three tests (General, Tech, Amateur Extra) in one sitting. I had to set for a physical test at a local club's monthly meeting, but now organizations like GLAARG are proctoring remote tests via zoomso you can gest more or less 'on demand' from home.