The hair is the richest ornament of women - Martin Luther
Picking the wedding hairstyle comes after the venue, dress, theme and flowers have been taken care of. The biggest decision is whether to have an up do or wear the hair down. Things to take into consideration are your facial structure, hair type and length, if you'll be using hair extensions and most importantly your dress.
I would advise that the more elaborate the dress, the simpler the hair should be so that everything is not overdone. Here are some pictures to help you:
Ensure you try out the hairstyle before the wedding so that you can get a feel for what you're going to look like on that day.