• Tonc, a tutorial on GBA programming by Jasper Vijn
• Damian Yerrick. Pin Eight: "Game Boy Advance Software Development".

Other Wikibooks on console platform development:

• PSP Programming
• Nintendo Wii Programming (coming someday)
• N64 Programming
• Xbox 360
• Game Creation with XNA for the Xbox 360

Other Wikibooks:

• Emulation has a list of emulators for the Game Boy and Game Boy Advanced -- Game Boy emulators that run on Linux, Game Boy emulators and Game Boy Advance emulators that run on OSX, etc.

Other Wiki resources:

• "the Gameboy Development Wiki".
• "GameBoy Advance Barebones" on the OS Dev wiki.
• "Pascal on the Game Boy Advance" on the Free Pascal wiki.

Other resources:

• "Gameboy Development on Mac OS X".
• Amit Singh. "UNIX on the Game Boy Advance".
• Loirak. "Gameboy Programming and Gameboy Advance Development"
• "GameBoy Developers Kit" (GBDK)
• Stack Overflow questions tagged 'gameboy'
• "Duo's GameBoy ASMSchool"
• "Making Gameboy games: installing the GBDK compiler in Ubuntu Linux".
• Chris Antonellis. "Gameboy Programming Resources".
• Howard Wen. "GBA Programming with DevKit Advance".
• "CowBite Virtual Hardware Specifications" describes low-level details of the hardware emulated by one GBA emulator, which in theory should work the same as the actual physical hardware of the GBA.
• "GameBoy Dev'rs".
• Patrick Meade. "Homebrew Engineer's Notebook: Game Boy Advance Development".
• "GBAGuy's Lair" includes some GBA ASM Tutorials.
• Doug Lanford. "Game Boy Development".
• "Gambatte". "an accuracy-focused, open-source, cross-platform Game Boy Color emulator".
• "DMGBoy (Dot Matrix Game Boy)". a Game Boy / Game Boy Color emulator.
• "GBA dev".
• "Gameboy Advance Development in Linux"
• "Porting Nut/OS for the GameBoy Advance"
• "Towers of Hanoi implemented for Nintendo's Gameboy Advance hand-held system."