Make a ball shape with Google SketchUp is not hard, but could not immediately so. Take several steps to make it.
First need to be made of two circles are perpendicular to each other. Then use the Follow Me Tool to form a ball.
For more details, please follow the following interactive tutorial. Please note, because it is an interactive tutorial so you need to click the Play/Next button (and following button) manually.
Google SketchUp Tutorial: