sandeaters.org will give you a detailed description of most of the dive sites in Los Angeles/Orange/Ventura counties.
From Miracle Mile I would personally enjoy the drive to Malibu and dive Malibu Road, Nicholas Canyon, Point Dume(see below), Leo Carrillo. The depths here will be shallow and not all that great for a deep dive in doubles. Deer Creek is good too.
All of these sites are diveable in doubles as the walk is short. Point Dume is a 545 yard surface swim from the beach and currents are a factor as the normal current will have you doing the 545 yard return swim against the current. If you cannot make it back to the beach, there is a bail out beach around the point, but if you miss this small beach, it is a long ride to Paradise Cove. Point Dume will put you on the lip of a canyon.
Visibility of late has been iffy, with 30 feet one day and 5 feet the next. Dive site selection will of course depend upon the swell model for the day. Visit the Sandeaters dive site listed above and good luck.
If you are looking for a deep dive, Vets Park in Redondo Beach will get you to 100+ feet and is a short walk down stairs. But this dive site while good at night can be dull in the daylight. Point Dume is on the edge of another canyon that will get you to below 100+ feet. You can swim straight out from the beach (ignoring the terrific pinnacles) to the canyon. I have done this dive once in the daytime, small stuff in the sand, but at night it would be good.
Laguna Beach offers seveal good dive sites. First off I would suggest Deadmans Reef, 300 or so yards off shore, then Seal Rock, or Shaws Cove.
Comparing Deer Creek to Shaws Cove? Hmm, Shaws cove is crowded on weekend with SCUBA classes and is more protected. Both are good dive sites.
