Preview is not only a PDF viewer (among others), but also allows us to modify the order of your pages, add them, or remove them. All this explained in this video tutorial.
In a previous post, my colleague Pere explained how to open two preview windows with the same document.
But the Mac OS X default PDF viewer (among others) also allows us to modify other things the order of the pages in a document, put new pages inside it, or even a whole document.
To explain all this I have decided to leave you a video tutorial that I made myself for my old blog Useful4Mac and for Apple-Informa, of which I was editor for a while.