How can I add Google a search bar on my website?

I want to add a Google search bar on my website.

How can I do this?

From stackoverflow

• Searching Google FTW!

• All instructions are here: http://www.google.com/coop/cse/

  I'm assuming you're familiar with google :D

• The best thing you can do is sign up for Google AdSense. Here you can find all you need to know about how to add a Google search bar. And you can make some money with it, if people click a link.

• Another one