It actually can be a little difficult to do. The social widgets are rendered using an iFrame that's loaded using Javascript. What that means is that the page/browser doesn't know how big they are until after everything's loaded.
Sometimes, depending on your overall layout, a simple text-align:center on the .scsocialbuttons class will make them align to the center, but that usually won't work.
The best solution, if you have a fixed width content area, is to set a margin-left on the .scsocialbuttons class. That makes it looked centered, but it's not relying on the browser to do so.
If you need help doing either of the above, let me know a page we can see the social buttons on and we'll gladly see if we can help provide the CSS to add to your template to make things look centered.
Thanks,
Alex
Center Social Sharing
