[billygoat]

Machine Language for Beginners, Charles Mansfield https://archive.org/details/ataribooks-machine-language-for-...

This book specifically targets beginners that are new to 6502 assembly. The examples cover all of the 1980s-era computers including the Apple II. It's free on archive.org and the introductory chapters are worth reading.

[kenjackson]

This is what I read as a middle schooler learning 6502 on a C64. Does a good covering the basics in a very conversational manner.