What to wear??
Jewelry: A simple yet elegant silver bracelet would be lovely. Also, sparkling silver dangle earrings. That’s all the jewelry you need. Don’t wear a necklace.
Shoes: Black high heels of any style would look amazing with your dress. The higher the heel, the better! 
Hair: With a halter dress, you want to show off your back and chest so you should probably put your hair up. Here are some pic ideas:
http://ecx.images-amazon.com/images/I/51X0ypTonpL._AA280_.jpg
http://www.lynnechapman.com/images/lghairupB.jpg
http://z.about.com/d/beauty/1/0/b/g/prom19.JPG
http://www.updosprom.com/img/prom-updos-pic-2006-3.jpg
http://www.hrpromhair.com/IceNataliePortmanupdo.jpg
Also, you could curl the ends or your hair and put it up in a high ponytail with a pretty scrunchie and jeweled hair clips.
*If you can’t get your hair to look right up then you could just curl it and leave it out. Or you could pull just the sides back with pretty clips. Anyway you do it, you hair will look great!
Just have fun, be happy, and you will look amazing!
Good luck!