Some places LPN's just pass meds. Others let them do nurse sick call.
At my facility they bombard me with questions all night. On the bright side every once and a while they make a fresh pot of coffee.
You don't need much psych experience, those with real mental health problems cause the least amount of problems... give me a pod of truly schizophrenic inmates any day. For the rest, read up on anti-social personalities; these people will kill, steal, lie, manipulate anyone for anything without any remorse. They will be extremely pleasant and charming until you say "no".
P.s.
Don't marry an inmate.