Is there a big map showing all the places?

Pleiades does have a "full map", but be forewarned: it's very rough. Our nightly exports include a dump in KML format that will overlay Pleiades locations over the globe in Google Earth (and other applications). There's very little cartography employed in this KML "map", but it's internet accessible and filled with direct links to Pleiades resources.

To use Pleiades data to make custom maps for classroom use, or for print or digital publications, you should try out the Antiquity À-la-carte web application, which is run by our partners at the Ancient World Mapping Center at the University of North Carolina at Chapel Hill. It includes not only all published Pleiades content, but also historical river and coastline data derived from the Barrington Atlas of the Greek and Roman World.