I, like many others, recently upgraded my Mac to OS X Yosemite. The upgrade seemed to have gone smoothly, until a few days ago when I tried to save a Web page to my “Reading List” in Safari. When I clicked on the Sharing icon, all I got was “No Services”.
I did a little research and found that this is a known problem with Yosemite. Fortunately, Apple already has a fix documented (see http://support.apple.com/en-us/HT6545). I opened a Terminal (Finder >> Go >> Utilities >> Terminal) and ran the command described in the fix. A minute or so later I had my Sharing option list back. The command to run is: