Share links to PDF versions of your files
In Drive, select your document.
Click Share person_add.
Click Copy link and click Done.
After you paste the link, change the end of the URL before sending it. For example:
Before: http://docs.google.com/document/d/12345678/edit?usp=sharing
After: http://docs.google.com/document/d/12345678/export?format=pdf
Send the modified PDF link.