Adding an onclick event to google.map marker

This is what I’d use:

var latLng = new google.maps.LatLng(53, -1.33);

var map = new google.maps.Map(document.getElementById('map_canvas'), {
    center: latLng,
    draggable: false,
    mapTypeId: google.maps.MapTypeId.ROADMAP
    scrollwheel: false,
    zoom: 14
});

var marker = new google.maps.Marker({
    animation: google.maps.Animation.DROP,
    icon: 'images/pin.png',
    map: map,
    position: latLng
});

google.maps.event.addDomListener(marker, 'click', function() {
    window.location.href = 'http://www.google.co.uk/';
});

I’m not sure if you can store a url property with a Marker object.

If you need to display multiple markers (i.e. from an API call) then you can use a for loop like this:

for (var i = 0; i < markers.length; i++) {
    (function(marker) {
        var marker = new google.maps.Marker({
            animation: google.maps.Animation.DROP,
            icon: 'images/pin.png',
            map: map,
            position: market.latLng
        });

        google.maps.event.addDomListener(marker, 'click', function() {
            window.location.href = marker.url;
        });
    })(markers[i]);
}

Make sure the marker is defined outside of initialize(). Otherwise, it will be undefined if you attempt to assign the click listener outside of initialize().

Also, you may have SAME-ORIGIN issues if you attempt to load url www.google.com, but it should work fine with a local url.

Updated code

var myCenter=new google.maps.LatLng(53, -1.33);

var marker=new google.maps.Marker({
    position:myCenter,
    url: '/',
    animation:google.maps.Animation.DROP
});

function initialize()
{
var mapProp = {
    center:myCenter,
    zoom: 14,
    draggable: false,
    scrollwheel: false,
    mapTypeId:google.maps.MapTypeId.ROADMAP
};

var map=new google.maps.Map(document.getElementById("map-canvas"),mapProp);

marker.setMap(map);
}

google.maps.event.addDomListener(window, 'load', initialize);
google.maps.event.addListener(marker, 'click', function() {window.location.href = marker.url;});

Working Demo on Bootply