Google Docs allows you to share files available on Google Docs by embedding it into a document viewer. This feature is also available for documents which are not uploaded to Google Docs, but hosted elsewhere. All you need to do is to make sure the document is available online. This embeddable document viewer works with PDF and PowerPoint files only.
You need to add only few lines of code to have the document viewer on your website.
Do not forget to replace the text in bold using the URL of the file you want to embed. As mentioned before, this will work only with PDF and PPT files.