You can use the Google Maps API v3 with Ground Overlays (your tiff image >better is jpg or png for web browsers)
In this example you can see the the imagebounds is the referencing the image.
http://code.google.com/apis/maps/documentation/javascript/examples/groundoverlay-simple.html
var imageBounds = new google.maps.LatLngBounds(
new google.maps.LatLng(40.712216,-74.22655),
new google.maps.LatLng(40.773941,-74.12544));
var oldmap = new google.maps.GroundOverlay(
"http://www.lib.utexas.edu/maps/historical/newark_nj_1922.jpg",
imageBounds);
oldmap.setMap(map);
Markers can be added to the Google Map that appear on your map(tiff/jpg/png)
http://code.google.com/apis/maps/documentation/javascript/examples/infowindow-simple.html
If your Marker Pins are coming from your MySQL database (using PHP) - see this method for the process
http://code.google.com/apis/maps/articles/phpsqlajax_v3.html