This is a common procedure in many institutions, and software exists to make it easier. You might find copying an image from a hard disk to each drive, temporarily removed from its PC, is much faster than from a DVD. See the following, in no particular order, for procedures, tools and information on licensing.
http://en.wikipedia.org/wiki/Disk_cloning
http://www.techsoup.org/support/articles-and-how-tos/configure-and-setup-multiple-computers
http://www.runtime.org/driveimage-xml.htm (free tool, if for private use)
http://www.macrium.com/reflectfree.aspx (free and paid versions)