If you are using your iPad a lot and want to save any web page to PDF and save it to DEVONthink To Go, you might want to have a look at Save2PDF. A tip from our forum user whshep:
With Save2PDF, I can get most of that work done without leaving the iPad. I choose “Print” in Mobile Safari, which saves the web page as a PDF and opens it in Save2PDF. I can then rename it (if necessary), choose “Open In” to get it into DEVONthink To Go, and sync it to desktop DEVONthink.