So I'm trying to reach Miraak. When I reach chapter V or last chapter before reaching Miraak, there is a marker pointing to a pedestal, but there is nothing in it.

Also I'm intending to upload a pic. How to do it?

http://elderscrolls.wikia.com/wiki/At_the_Summit_of_Apocrypha

You need to place a book on it.

Are you using mods?