It's a bit tricky, but doable. The current Makehuman has all the facial morphs for visemes and such disabled. So, unless you have some mad modelling skills your going to have rather stoic, silent avatars.
Version 1.1 (not available yet) should take care of this with a facial bone rig. That will make it much easier to use Makehuman generated avatars.
This video, although Blender based, shows how to set up an non-standard human in 3DXchange. So you will need 3DXchange as well.
I would also suggest posting with a main title about what your after, and also not in the iClone 4 forum.