I would just attach a marker click event to each of your markers.
google.maps.event.addListener(marker, 'click', function() {
alert('trigger url associated with marker');
});
Normally if you have a lot of functionality within a map you store your markers themselves within an array so you can refer back to them. I would do that of course, but on top of it I would have another array directly associated with the markers that stores your urls. You could then use jquery to trigger the click of a hidden html link that prior to triggering you populate with your url stored in your marker url array. Let me know if you need more on this,as it is kind of difficult with no code to look at, but I am very sure the method I have laid out will work.
***Update here is how I would do it. :
html>
<head>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.3/jquery.min.js"></script>
<script>
function marker_onClick() {
$('#myMarkerUrl').click();
}
</script>
</head>
<body>
<a id='myMarkerUrl' href='http://www.google.com' onClick="a_onClick()"> aaa </a>
</body>
</html>
</body>
</html>
Then override in the url in the google maps addevent listener portion of code.
google.maps.event.addListener(marker, 'click', function() {
var myMarkersURL = myMarkersURLArray[i];
$("#myMarkerUrl").attr("href", myMarkersURL);
$('#myMarkerUrl').click();
});
Now that you have that above, keep in mind I haven't tested this but it is generally what I would do in your shoes.