How to find waypoint IDs?
One possible source is Skyvector



You can use it like a paper map using the Latitude and Longitude markings to find waypoints (or other positions).

E.g. What waypoints and routes are near S30°0.00' E112°00.00'



Hints: Click "World Hi", use your mouse's scroll-wheel to zoom, play with "Layers".



There are also sites with lists, by region, of waypoints with coordinates. One example is fallingrain