SJ Peak Overnight protocol

[Rck]

Hello All
I hate to as such a basic Question but what is the protocol for overnight camping in the San Jacinto Peak area. If I remember, 30 years ago, you have to get a permit go cross through one of the areas but not the other and to get the permit you go to a small building sign in and take one. Now for the overnight camping. Do I need to make come kind of reservations or something. I have been hearing that I do and some say don't worry about it. I plan on going with son and his friend at the end of May so don't want to get caught short.

Thanks
Rick