Hi Mike. Thanks for the question. I will cover the basics in Spring Quickly in 30 - 50 pages. Of course, Spring Security is a complex topic. One complex enough I've written a book of 560 pages on it. If you already know the basics for Spring you can go directly with learning Spring Security by reading Spring Security in Action. If you don't yet know the basics of Spring, then I recommend you first read Spring Quickly and then read Spring Security in Action. I also share tons of knowledge on my youtube channel: youtube.com/c/laurentiuspilca There you'll also find a nice playlist on Spring Security fundamentals

Cheers!