Opt out for mass emails

What needs to go into a footer for a mass email to keep me in compliance with the Anti Spam laws?

Our web site doesn't have an "opt out' page that I can borrow code from, so that unsubscribe option is unavailable. How can I offer unsubscribe in another way?

Can I put the name and address of our firm in the footer and an email address to the person who would handle that?

Does anything else need to go into footer for antispam purposes?

Thanks,