Hot to add a download button to my blog?

I’m looking to add a download button to my blog (a button which when is clicked you get redirected to a download page) (jut like the one from http://www.fusioncheat.com/2011/12/cityville-hack-perfect-working.html)

How can i do that? Is there a plugin that can do this for me? Or some code lines? Thanks in advance?