rendering a roleplaying map I would like to use blender to model a map of a castle, and then have a cutaway view of the map, with all the objects inside. Then, if possible, have the view almost orthographic. 

Yes, I could just illustrate the map using photoshop or illustrator, but I wanted to see if I could use Blender in my pipeline. 

How would you go about rendering in Ortho view from top down?
Numpad 7 to go to top view

Numpad 5 to go into orthographic

RMB on your camera

and Ctrl+Alt+Numpad 0

This will move your camera to your view

Now if you F12, you can render whatever your camera is looking at