Game Development Reference
From here we can lay PathNodes, which our pawn will use to navigate. Open your
Actor Classes browser and type in PathNode to bring up the available actors.
With the PathNode selected, left-click and drag it onto the map. It should spawn the
node in the center of the map, along with the translation widget. Move it accordingly,
while creating new copies along the way.
I've aligned mine in such a way that the pawn will search the perimeter of the map,
while still offering a path down the middle of the map, between the BSP.
Also be sure that you have a PlayerStart navigation point on your map. There should
be one in place on your map by default as UDK places it there automatically, but it's
important to be aware of its exact location, as that will come into play later.