What I would like to do is create app where when anyone clicks on the map object and two fields get filled with latitude and longitude at every click. Is there sample code of Google Maps V3 JavaScript API (Geocoding API) somewhere out there that does something like that?
You can achieve this with google.maps.event' LatLng property:
Something like this would show how it works. Here is a JSFiddle Demo:
google.maps.event.addListener(map, 'click', function(event){
alert('Lat: ' + event.latLng.lat() + ' Lng: ' + event.latLng.lng());
});
Where map is your google map object. Yes the example is in V2 i think, and if you would like to create a marker on click you can simply create it within the click callback function.