When staff is looking for minimods they usually make an announcement about it.
I found this newspost about MM requirements
Quote
Requirements
*You must be at least 16 years of age by the time applications close on July 16th.
*You must be a current resident of the US.
*You may not work or volunteer for any other pet sites while working for Subeta.
*Access to a reliable internet connection.
*You must be able to adhere to strict non-disclosure policies.
*A firm grasp of the English language.
*Respect for the Subeta community and the ability to communicate clear and polite direction when needed. As a MiniMod, you are a representative of Subeta; your words and actions, both on and off of Subeta reflect directly upon our team as whole.</p>
<p>This is a purely volunteer position. While we dont expect you to be online 24/7, the more time you have available, the better.
From 2012
There may be changes/new requirements, but hopefully this gives you an idea! :)