Tutorials
From GbdevWiki
Assembly Language Programming
Machine and assembly language programming concepts that illustrate basic principles and techniques. Application through study of the Z80 chip and Gameboy programming assignments. Wichita State University
http://cratel.wichita.edu/cratel/ECE238Spr08
8-Bit Wonderland
Executing custom code on the Nintendo Game Boy A nice tutorial covering the basics of designing hardware and software for the GameBoy.
http://belial.blarzwurst.de/gbpaper/paper.pdf
Written by Belial belial@apocalypsys.net
Tutorial de ensamblador
A (work in progress) tutorial of GameBoy assembly programming written in spanish. It covers the basics and using some of the GameBoy hardware like mappers, timer, etc.
http://wiki.ladecadence.net/doku.php?id=tutorial_de_ensamblador
Written by David Pello: zako@ladecadence.net