photoshop is much better, there are a lot of usable features that your son can experiment on. CR2 files can be imported using the Canon software that comes with the camera but with only limited editing. i'd say go for the latest photoshop edition and you'll never regret it.
For bulk professional photo retouch I use Photoshop CS5 with self made actions. For my opinion Lightroom are toy for new photographers.
I would recommend Eye-one display 2 from X-rite, but be careful with 64-bit drivers.
* Includes emission-only colorimeter with ambient measurement capabilities * Professional monitor-calibration tool with advanced controls * Achieve accurate color on all displays including LCDs, CRTs, and laptops * Optimize gray balance for more neutral and better-defined grays * Check ambient light to determine optimal room lighting for color-critical work