What do we need to do to transfer property to me and my brothers and sisters from my mother?

I am very sorry for your loss. In California the level of probate depends on the type and value of assets. If the assets total $150k or more then a full probate is required. If less than $150k there are a couple different options depending on if it's real estate or non-real estate (ie bank accounts and such). I would be happy to give you a more detailed answer if you can let me some details on the assets. Feel free to contact me directly if you prefer to keep it private. -John