GB-Dev

Gameboy game development with C

SDK

This set of tutorials use GBDK

http://gbdk.sourceforge.net/

Documentation on GBDK (incomplete): http://gbdk.sourceforge.net/doc/html/book01.html

Tools

Emulator & Debugger

http://bgb.bircd.org/

GB Tile Designer

http://www.devrs.com/gb/hmgd/gbtd.html

GB Map Builder

http://www.devrs.com/gb/hmgd/gbmb.html