Shift-A only gives option to add Mesh? Pressing Shift+A immediately takes me to the add mesh options. I'm trying to add an armature, but I cannot seem to be able to find a way. Even the "create" tab only has an Add Meshes option. I remember that the first time I used Shift+A, I had to hover over meshes first, then select my object type...but I've never had to take that first step since and I do not know how to undo it. Help?
Make sure that you are in Object Mode if you'd like to add a new primitive or new object to the scene. 

From the manual: 


  Creation of a mesh primitive typically starts by adding a mesh object
  in Object Mode. Limited types of editing such as size, location, and
  orientation can be accomplished in Object Mode. Object Mode also
  provides the means to Join and Group multiple mesh primitives.