Programming the 6502

Original Apple II manuals written by Chris Espinosa and Jef Raskin are a treat to read. Would highly recommend, just to get a sense of what it was like to get onboarded on Apple II back in the day. And then obviously Programming the 6502 by Rodnay Zaks.

Read it as a young teenager, can recommend.

Seconded. I bought the first edition of "Programming the 6502" way back in the neolithic, and I enjoyed it greatly. I even read parts of it again now and then these days too, just because I like it. I used to write assembly on, at first, the AIM-65, and later the Apple II.

I believe one of the "standard works" to learn 6502 back in the day was Programming the 6502 by Rodnay Zaks. It's out of print, but it was printed in a lot of copies so you should be able to find one second-hand.