Fill out the form to set up the allowance for your child. Some pointers:
Names: "Your name" and "Recipient's name" are for the purpose of the e-mail sent to your child announcing the allowance deposits, so you can go with the names you would use for each other, not your iTunes user names.
Amount: Unfortunately, you can't customize an amount, but have to choose from set figures from $10 to $200. Keep it to the lower end of the scale, and you can still give your child little gift certificates during the month to recognize special achievement. You can easily adjust the allowance amount later through your iTunes account information.
First Installment: Payments will be deposited on the first of every month. If you're doing the allowance set-up after the first, you can decide whether your child still gets a payment for the current month -- payable immediately -- or has to wait for next month's money. Be aware that the new account you will be setting up will not be available for use until that first allowance payment goes in. For immediate use, either start the allowance immediately or set up the account with a gift card instead, and add the allowance later.
Recipient's Apple ID: If you will be setting up a new account for your child using the rest of this step-by-step, click in the circle that says "Create an Apple Account for recipient." If your child already has an iTunes account, click on the circle that says "Use recipient's existing Apple Account," and enter the ID and password information.
Personal Message: Write a little something congratulating your child for hard work and earning this allowance. It will appear in the e-mail sent to your child announcing the allowance.
Terms and Conditions: You can scroll down and read all of the fine print; if appropriate, go over it with your child as well.
When you're done, click "Continue."