Any external USB DVD drive should work nicely. There isn't quite enough information about your model to say if you can use and internal drive but typically if you can they do come with it by default.
Just about anything you can have on a CD/DVD or Blu-Ray can now be put on a Thumb Drive and inserted in to any USB port. Unless you need to burn CD/DVDs I recommend just using thumb drives. Best Buy has a number you can choose from. 32GB should suffice for most needs but they do make the larger.