1.Login to your blogger dashboard--> layout- -> Edit HTML

2.Scroll down to where you see </head> tag .

3.Copy below code and paste it just before the </head> tag.

Check Visited Links of Your Blog/WebSite

<style type='text/css'>
a:visited {
padding-left: 15px;
background: url(http://1.bp.blogspot.com/_4HKUHirY_2U/SxMoZG2TMoI/AAAAAAAAAcE/t1qcIEAb6aU/check.png) left no-repeat;
  }
</style>

4.Now save your template.

You are done.

Demo