I am not a professional but I am interested someday to try psych nursing as I took care of one of my friend who has schizophrenia for close to a year.
Have you try your local NAMI (National Alliance for the Mentally ILL) office? They are at www.nami.org
You might get some down at the trenches kinds of advices from NAMI since most of them are parents with loved one who has a serious MI. If your local chapter has a Family to Family class, you might try to take it (it is a 12 week commitment, unfortunately) dealing with the mental health system, the police, communication with the ill family members, ... etc.
There is a classic book in which you might know already call "I am not sick - I don't need help!" by Dr Xavier Amador. It is a good book on how to communicate with an illed relative who is suffering from a serious mental illness. If you want to get really technical, there is a hard to get book call "Cognitive Therapy for Delusions, Voices, and Paranoia" by Paul Chadwick, Max Birchwood, and Peter Trower. Some of the principles and techniques you might be able to use. The Brits are a little bit ahead of the US in terms of CBT and serious mental illnesses.
Hope some of it helps.