Your soon to be spouse- You must apply in person at the same time.
Proof of residence- Driver's license, lease, utility bill, etc.
2 Forms of Photo ID- Passport, License, etc.
Social Security Card
Certified copy of birth certificate
Location and date of marriage
Officiant's name, address, and phone number
Names for both parents- Including middle names and maiden names
If you don't speak English- A third party to interpret
If under 18- Signed consent from parent or guardian
If previously married- Copy of judgement of divorce, annulment, or death certificate
Note: Call ahead to ask how long a marriage license lasts. It is different in different states. Make sure to plan it so that your wedding is before the expiration date.