rental car company insurance?

[Eric]

I am starting a rental car company in california and i need to know what type of insurance i will need. all of the cars rented will be wholly owned by my rental car company and we would want liability coverage on these vehicles only. also if there is a way for renters to utilize their own insurance how would that work. also if there is a way to sell them coverage how does that work. any guidance on companies that offer insurance would be helpful, and the types of insurance that rental car companies usually purchase would be helpful. we need to be able to register cars at the dmv and also we want to have the liability covered for accidents with others, we are not as concerned about collision.