I like the Lean Software books by Mary and Tom Poppendieck. There are a few of them, they cover similar ground to each other but from different perspectives (talking about what it is, versus how to apply it as a manager, etc.). "Waste" is a critical concept to Lean in general and they've done a good job of applying it to software. All their books (I think) are available through O'Reilly.

I would recommend this free chapter from the book Rethinking Productivity in Software Engineering https://www.researchgate.net/publication/332916053_Removing_... which describes a workshop to identify and remove wastes. The whole book is open and fun to read.

I highly recommend the book Principles of Product Development Flow. It's a bit dense and very dry, so take your time with it.