Here’s a nice button for WordPress using the Max Button plugin…
Max Button[maxbutt*n name="MaxButton"]
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.