Wikimedia Commons has media related to:

Graphic design

Graphic design is the applied art of arranging image and text to communicate a message. It may be applied in media such as print, electronic media, motion picture, animation, packaging, signs, identities, etc.

Resources:

• meta:Philip Greenspun illustration project. Creation and improvement of illustrations for Wikimedia.
• Wikipedia:Graphic Lab/Image workshop
• See the resource list at commons:Category:Charts.