Adding thumbnails can make data presentation more attractive to your website visitors. I like to add a thumbnail of the screenshot of a website I am writing about.
www.websnapr offers this as a free service. Just pop in the URL address and click the buttom. I use save image as ( right click).
“websnapr lets you capture screenshots of (almost) any web page. Allow your visitors to instantly visualize any web page before clicking. Increase site traffic, click-through rate and site stickiness.”
Upload the saved image to your wordpress site. Change the link URL to the image website and don’t forget to check the target button on the bottom of the advanced image options so the website opens on a new page.