Here are some resources that I used when creating my mod:
VTMB Mod Developers Guide: A compilation of most information known about modding this game.
External Appendices
VPKTool 3.9a: === THE === modding tool for VTMB.
Needed to extract/decompress game resources. Also allows limited editing of maps and model texture paths.
Python 2.1.2: The scripting language of VTMB
The main thing here is the IDLE editor, which provides indention and Color coding support when editing python scripts.