MCForums:
http://www.minecraftforum.net/forums/mapping-and-modding/minecraft-mods/2310397
GitHub:
https://github.com/da3dsoul/Additional-Buildcraft-Objects
Permission for modification and distribution from original author:
https://github.com/da3dsoul/Additional-Buildcraft-Objects/issues/40
This will not have extensive information about the mod. It is a long standing one and info can be found elsewhere.
I forget stuff exists sometimes, so checking the github is the most reliable source.
Post bugs on MCForums or GitHub if you find any. I prefer github out of convenience (they also email me faster).