Not standard, but hopefully worth mentioning: the thing that's clicked best for me is the docs on https://ciel-lang.org/ ("batteries included" Common Lisp image). The examples for how to use it's curated libraries matches how I try to integrate a new language into my toolbox.

It hit the front page a while ago too: https://news.ycombinator.com/item?id=41401415

Gentle Introduction to Symbolic Computation is a great book, I learned a lot. The 1990 version available for free below has aged well but you need to look elsewhere for getting setup with emacs and slime or whatever environment you want.

https://www.cs.cmu.edu/~dst/LispBook/

I began learning Common Lisp (CL) from the Common Lisp HyperSpec (CLHS): <https://www.lispworks.com/documentation/HyperSpec/Front/Cont...>. When I began learning CL about two decades ago, I did know of any other easily available source, so CLHS was my only source back then and I think it has served me well.

A popular recommendation these days is Practical Common Lisp (by Peter Seibel): <https://gigamonkeys.com/book/>.

There's this great post by Steve Losh:

https://stevelosh.com/blog/2018/08/a-road-to-common-lisp/