Armature not completely moving head mesh So I have a singular head bone on top of my character so I can rotate the head as a whole. But when I rotate the head bone after applying the armature, it does not correctly move parts of the mesh:

https://puu.sh/sEevu/02bc7256ec.jpg

https://puu.sh/sEeAw/8fd79caeff.jpg

I had made sure all parts of the head was joined together into one mesh and I also removed all doubles.  Should I join the body and the head meshes? I hope this is a simple mistake because this is confusing the hell out of me. I guess its also worth noting that this is my first rig.
I noticed that marios right arm gets twisted when the armature gets parented.
To fix that, you need to go into pose mode of the armature, press CTRL + A and select apply pose as rest pose. 

Even though the eyes,mustache, and face are one object, the eyes/mustache arent connected to the face but floating in mid air. So the automatic weights didnt work perfectly. You can see that because when in weight paint mode, the eyes are blue (meaning the vertices arent assigned to that bone) and the mustache is green (meaning it is only partially controlled by that bone)

You can easily fix that by manually selecting all the vertices in the face with A  and assigning all of them to be fully controlled by the head bone in the Properties Editor->Data->Vertex Groups->Assign. I also noticed the mustache is partially controlled by the chest bone so I removed it from its control.

The process is called "weight painting".