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.
Is Programming the 6502 enough to learn Assembly on the Apple II ? But it doesn't explain the memory and screen management, right ? So how can we learn that ?