Mission Beach/Pacific Beach can have a nasty break if you're diving from shore. Once you're past it the contour is mostly featureless bottom. It's a good place to spearfish for halibut or sole but otherwise kind of boring. It's better than staying dry, but not much. Further north toward Bird Rock and the La Jolla peninsula south of the Cove can be "sporty" on entry, but there is more to see. La Jolla cove (kelp forest, sharks) is better than La Jolla shores (sand, highlighted by mud, punctuated by rocks).
La Jolla in the summer time... I think I'd rather have my fingernails eaten away with a power grinder. Best left for after kids go back to school (visibility is better then too).
Boat diving is where it's at. There are 3 large boats that operate in San Diego, it's a mixed bag of what you'll find in the summer time.
If you're going to go the boat route and have specific needs, I'd recommend Danny Howard or Jeff Swan's 6 packs. They're very reasonable for weekend charters.
The local dive boats are the Marissa (14 max), Waterhorse (22 max) and Lois Ann (I *think* 16 max? It's been a while). All of them are good boats, roughly comparable for generic diving. Better if you can get them midweek when the loads are lighter.
Kelp sites hold more divers better than wreck sites. I'd recommend not diving wrecks from the Waterhorse as 22 divers on any local wreck that's not the Yukon is just un-fun (and even then, the Yukon only provides enough room if you're qualified to be inside her).
Power Scuba is a great club with some good people, but their boats are jammed like a Berlin nightclub and also a very mixed bag (they keep their costs down by putting more than the max load on a normal charter - so it's like a busy weekend on steroids). If you're going to shore dive, that club is probably a great move for you as the members know the sites and are generally enthusiastic about sharing their knowledge with new divers. Boat diving with them is trickier as their prices are very low and boats fill up with the budget crowd usually within a few hours of when they're posted. Don't get me wrong, they can be a lot of fun just be forewarned about the elbow room.
If you need to rent gear, depending on what you want, look at San Diego Divers or Dive California. Both owned by competent and trustworthy folks with decent equipment and access to gas.
If you need a guide, San Diego diving might not be for you as you'll need to hire one and they're not cheap.
Hope that helps. Feel free to PM me if you have any specific questions.