Most golems have the rules for their creation in their Monster entries. There's also the Effigy template that you can apply to various stuffs.
There really aren't any cohesive rules for golem building, and there's virtually no room for customization of your golems (you can advance HD and apply appropriate benefits, but that's it).
There's a Dragon Magazine issue with golem addons in it. The best is easily Rudimentary Intelligence; slap that on any effigy creature and you've got basically the most customizable construct you could possibly build, and it will still be pretty absurdly expensive.