Here’s a nice button for WordPress using the Max Button plugin…Max Button
Use the “MaxButtons” menu item in the dashboard to access the control panel. Define buttons with lots of options including the link URL. Give it a name (e.g., “MaxButton” above) and place it in posts or pages with the short code. The text “maxbutt*n” is really maxbutton, but changed so as not to trigger the short code in this post.