PAM modules

Since I don't use gui's or graphical interfaces on my system (don't have the
choice), I need to know what the default password policy is for Redhat
(current release version). Second, how can I change that policy by
modifiying the PAM modules (or can I??). I'm thinking of something like
password expire every 90 days, password history of 8 generations, forcing a
user to create a complex password, that sort of thing. Is there a tech
document that can guide me here?