it depends, what religion are the people?

Generally you need a certificate that the woman is eligible for marriage (i.e. is not already married), and permission from her father.

If the woman is not muslim she needs to write a letter to a judge requesting permission to get married, citing her work, the religions of her parents etc.

Thats all i know but the sharia court on Al Rayyan road is the place to find more info. Its a horrible place though with some righteous *&#@ holes working there, and women have to be veiled even to enter.