I have a model and a normal map, can I bake Ambient Occlusion from both? So I know how to regularly set up ambient occlusion baking in Blender, and I have applied the normal map using Blender Render. However, whenever I try to then bake AO, it does not take the normal map into account, giving me the AO for just the model.

Is it possible to bake the AO, taking into account the normal map, so that all the details are baked into the AO map also?
you need to bake in AO from the geometry, not the normal map...you can bake out the original mesh or possible apply the normal map as a displacement to the current mesh...just add a multires modifier before the displacement and subdivide it a few times.