August 2nd should see the beginning of the rollout of the Windows 10 anniversary edition. What can you expect? Quite a few tweaks and changes to things like the Start Menu (again!) and "Live Tiles" and various notification changes - also some extensions to improve the functionality of the new Edge browser. It does not sound to me like a lot of actual "cool" stuff or major changes, but hopefully it will make most Windows 10 users feel like they are getting a little "something something".
Most users will not need to "do" anything, if your computer is left on most of the time it should update itself in the next few days (and possibly weeks). To initiate the Anniversary Update manually you can go to Start -> Settings -> Update & security -> Windows Update, and then click Check for updates.