First do a forum search or if you find that too complicated or not very intuitive do a Google search using the forum as the site.
If the searches bring back nothing make sure you've read the Texture Pack Installation and Patching Guide.
Next, when you ask for support make sure you supply some basic information:
- The version of Minecraft you're using
- The version of the base BDcraft texturepack you've installed (or just provide the link you used)
- The version of MCPatcher or Optifine you've used (if you're using either)
- If it's a mod issue, state which version you're using and what textures you've installed and from where
- Screenshots of issues are also very helpful