My world is pretty close to a medieval Earth during the Eocene. So far I have several different regions that are pretty well fleshed out, but I still have to put everything together with a world map that makes all the pieces fit coherently. I've been playing with Photoshop a bit to get a map set up, but I'm pretty new to building outside of a pen and paper medium, so it's been slow going.

Any advice on tutorials/guides for generating maps? I only need a rough outline to get things going, but the more detail I can work in the better.