Part 2 of a great new tutorial from Juwal Bose on TutsPlus: "In this final part of the tutorial series, we'll build on the first tutorial and learn about implementing pickups, triggers, level swapping, path finding, path following, level scrolling, isometric height, and isometric projectiles."
Creating Isometric Worlds Tutorial
In Part 2 of the series you learn how to add pickups, triggers and path finding.