The "Everything sidebar" is actually Google's experimental UI Jazz. [searchengineland.com...] You were randomly selected to participate in this experiment.
Clear your cookies and you will return to the old Google search page. This worked for me. In Firefox, I clicked Tools > Options > Privacy > Show Cookies > searched for Google, then deleted all the cookies that had Google in them. Restart the browser and the old Google page is back.
Or, keep the cookie and appreciate that you're one of the select few who is seeing a new, experimental Google screen. Try out the cool location option on the results screen, even when you're not signed in. What other new features are there?
Now I wish I hadn't removed myself from the experiment.