Have you tried Google Doc Viewer? It's very simple to use and free! Add a markup code like the following in your webpage:
<iframe src="http://docs.google.com/gview?url=http://infolab.stanford.edu/pub/papers/google.pdf&embedded=true" style="width:600px; height:500px;" frameborder="0"></iframe>
Then you just need to set up your own document file to the "url" query string param and that's it!