How can I get a button to open a pop-up window or a new tab?

I'm attempting to make it where when you click on a button "learn more" it simply opens a pop-up window or opens a new tab. The way it's currently set up, is if you click on a button it takes you away from the page you're on. I want the current page to stay up and another tab or pop-up window open with the info that the button elicits. 

Hey Johnny, sounds like the Lightbox Anything plugin would be good for this. Not an affiliate link, have just used before with good results.