Even if you have straight hair, you'll want to iron it and spray on shine serum to get a maximum sleek look. The secret to this style, modeled by actress Penelope Cruz, is large curlers and hairpins. Once the large curls are made, you'll want to curl them & pin them in place (again long, straight hairpins are best, see other hairstyles before this one on how to use them & where to get them), then spray. Again, don't make the mistake of making your updo stiff & tacky with heavy-duty hairspray. You'll want a flexible hold formula that can withstand humidity, but leaves hair touchable.
I like this look a bit further back on the head, rather than piled all on top -- a look that can make a long face look REALLY long. You can get away with the piled look if you have a round, square or oval face.
To get this lift up top as seen here, you can tease hair at the roots. If you want to avoid the damage backcombing can do, consider a "Bumpit" an amazing insert that will give hair volume and lift all night.
Read about Bumpits here.
Prom hairstyle photo gallery hub