Newbie Object Rotation Question

I’ve imported an ac3d model and am attempting to orient it with angular data read from a text file. The problem I’m having is that not all the objects in the module have a common axis orientation, and move differently when their rotation properties are changed.

Is there a way of reorienting the axis system for individual objects without actually performing the rotation? Is it possible within a script to group the objects then rotate the group as a whole?

Does anyone know of any documentation which covers the Blender coordinate systems in detail?

Thanks

Parent the objects to a single object, then animate that one object.