Use a PDF printer--like Adobe PDF PDF Factory, or PDF 995 ( free ).
Another ( better, IMO ) option is DWFX for Autodesk Design Review ( free download from Adesk ).
This way the person viewing the DWFX can see all the "information" of model elements, and if you create a 3D DWFX
file they can slice/cut sections, spin around, etc. Its a great "free BIM viewer.
As mentioned above, you will need to install a PDF virtual printer on your computer. I recommend PDF Creator (link) because it's free and easy to use. Then you just print your files like you normally would, but choose the PDF printer instead. It will give you a pop-up window asking where you want to save the PDF, and what you want to name it.