How do I find out what version my Skyrim is patched to?
Start/load a game, press ESC to bring up the system menu, and it's there near the bottom left hand corner.
There's no direct way in Steam. However it's possible by checking the Skyrim executable's metadata. Go to you steam installation folder, then browse to \steamapps\common\skyrim .
Right click the TESV.exe file and select properties. The version number should be displayed in the details tab.