Recommended first steps with the BeagleBoard
I would start with Angstrom Linux, and then move to Ubuntu if you have to. I doubt that you will need to switch just to make the camera work.

I believe the OS for the Beagleboard XM is stored on the SD card, so if you decide you do need to switch to something else, you might get a second SD card, so you can leave the original OS intact. Depending on the OS, you can probably find a prebuilt SD card image that will allow the Beagleboard to boot.

For an IDE, I would recommend starting with a text editor that works over SSH. You might start with Nano, unless you've used Vim or Emacs before.

I'm not sure about debugging C++ on the Beagleboard, but you can start compiling in Angstrom  with g++. You'll be able to execute code from the commandline.