The best book on Lean for beginners is “2 Second Lean” by Paul Akers. You can buy the book or get it free directly from Paul Akers’ website.
https://paulakers.net/books/2-second-lean
And for an impressive display of what Lean can do, watch this video “Lean Manufacturing - Kaizen Methodology - Lean FastCap Style”
https://www.youtube.com/watch?v=su9CulCZTBg