On the Insert tab of the ribbon, click the Online Pictures button. In the box that opens, enter a search term in the "Office.com Clip Art" section or the "Bing Image Search" section.
The amount of clip art on the Office.com site does seem to be less than was available in previous versions. The Bing search will show results from much of the Internet, but you have to be more careful about not using copyrighted material without permission.
