Take a look at http://www.naturalearthdata.com/]Natural Earth[/url]. They provide a good chunk of public domain spatial data.
You'll need a GIS like QuantumGIS, uDig, or OpenJUMP to view and manipulate it. You can find an introduction here http://www.cartographersguild.com/sh...-for-using-GIS
I just came back from vacation, and this post was very helpful. I downloaded QGIS and a 10m data set from Natural Earth. After wasting a couple of hours playing around with it, I zoomed in on Europe, set the projection to something like what I wanted, and saved a print composition as an image. Now I have a very large, very accurate map in photoshop including everything I wanted. I have Europe including Iceland, as well as North Africa's coast, and Asia as far as Persia. And all the little lakes, rivers, and islands.
Originally Posted by Hai-Etlik
With this technique I can maybe go back to my alternate North America I was making long ago, since I can now create a large map that doesn't distort Canada horribly and doesn't exclude many of the islands on the west coast and northern territories.