windows 7 - Convert PDF and Word documents to TIFF images

On Windows 7, how could I go about creating a TIFF image from a) MS Word documents, and b) PDF documents? I need the equivalent of printing out and scanning the document, so I can mimic signing the document and scanning it using a graphics editor.

My preferred graphics editors are Paint.NET for raster and Expression Design for vector. I know the main document is raster, but I could do my signature in vector and add it as a layer in Expression I hope.