How do I activate a Steam key?

I bought the Skyrim Legendary edition and it came with a steam code. Where do I enter this Steam code?

Solution 1:

Assuming you are on the Steam desktop client: Go to Library, then look at the bottom left corner for: "+ Add a Game..." From there go to "Activate a Product on Steam" and follow the instructions.

Solution 2:

When logged into Steam, go to the top bar, click on on the small word "Games" (above Store and Library). In the drop down menu click on "Activate a Product on Steam...". On the pop up that appears, click on the "next" button on the bottom. After That click on the "I agree" button. Then enter in your Steam code into the text box that appears.