If I am a landlord in NH and only own one property what can I charge for security, rental and pet deposits?

In New York if the landlord doesn't have more than 3 units he/she can charge whatever he/she wants. Its what they but on there lease. But the norm is 1 month rent = security deposit. However, I have seen places that require 2 months for a security deposit or even require tenant pay for the rent in advance.

What is a pet deposit? Is it a security deposit for a tenant that has pets?

Remember that this is a deposit and when the lease is fulfilled the tenant does get this back enless there was damage. In which case the repairs come out of that and the balance is returned.