Machine Language For Beginners (atariarchives.org)

Here are some tools to go with that:

http://www.atariage.com/2600/programming/index.html

Clearly since ASM isn't bad enough already.

I loved this book when I was starting out.

I respect compiler folks, deeply, but I hope I never have to program in assembly by hand. Here's the first code example:

" LDA #$01

LDY #$00

STA $8000,Y

STA $8100,Y

STA $8200,Y

STA $8300,Y

INY

BNE $0364

RTS"

shudder

And here's the kicker - that's not even the x86 instruction set. If you are learning legacy assembly language, you are a true geek. Or something.

This book and its sequel is responsible for wasting an entire summer of my life when I was 12! I miss those days :)