Help plz

hi i'm new to this forum and found it while searching on the internet. I'm a 20 year old student living in california. Recently my father threw a tantrum and requested for a divorce. I guess i should describe my family situation. My father was never close to me and my sister and never treated us like his children. He is very irritable and angry at the world and because of this stormed out on my family frequently on the littlest of things. My mother is a strong woman and i love her to death but she is not confrontational is is willing to put up with it in order to salvage what sense of family we have. Well throughout my childhood my father squandered the savings on rental property and got fired from his work for mental reasons. He then moved out of the house when i was in middle school and developed relations with another and lived in his office. It was untill a couple years later we get a call and he is in jail and we bail him out. He is placed in jail for attempted assault on this other person he had relations with. We post his bail and he moves back home. In midst of all this my mother and father are still married. My mother is supporting my sister and I and paying off the house bills. In the mean time my father did nothing to support us but only financially was supported by rent from his rental unit and his side business of income tax. WHen my father moved in he was fine for a while mentally after experiencing jail but is still highly irritable as the littlest of things will set him off. So untill recently my father requrested for a divorce after a temper tantrum he has and wants to split everything fity fifty. I feel this is a good decision to divorce because my mother doesn't deserve this anymore. However i fear about our "community property" my father has not contributed a dime towards paying off the house after he lost his job in the early nineties, and my mom has done well supporting my sister and I. It is unfair for such an irritable person to take advantage of my mother who only avoided confrontation such as a divorce because of my sister and I. My father also does not have a penny to his name as once he recieves money he decides to spend it on things. I really believe something is mentally wrong with him but he lets no one talk to him. He has visited a psychiatrist for a short while but would not commit to it. I feel like my mother is in a losing situation and i just don't want her to worry anymore. Plz help or refer any websites or information that will help my family out.