I am actually working on just such a document as mapping problems come up in lots of our projects and depending on each of the available routes comes with its own pros and cons. Will be publishing it in the next couple of days.
In the meantime, I would suggest a careful look at the Openlayers ( http://drupal.org/project/openlayers) module if I were you. It is powerful and once you get into it gives you a lot of flexibility. Best, Ronald --- http://www.istos.it drupal-based web development
