Hi MB,
Good questions! It's been my experience that there's not much diving in the SF Bay; however, like Brian said, if you're able to make the trip to Monterey (2 hours south +/-), you'll be in for an unforgetable experience.
There are many dive locations off the Monterey Peninsula. Breakwater (San Carlos Beach), Monterey; MacAbee Beach, Monterey; Lovers Cove, Pacific Grove; Coral Street, Pacific Grove; Pt. Lobos; Monastery Beach, Carmel -- just to name a few.
Also, like Brian mentioned, you won't find much in the way of wrecks, but you will have some great dives. Water temperatures range from the upper-40's to the mid-50's, and since you're from the NJ area, I'm sure you're acclimated to colder waters.
For under $12, I encourage you to consider the following book:
Diving & Snorkeling Monterey Peninsula & Northern California; by Steve Rosenberg. It offers a good glimpse to the area, and includes helpful tips, and 'what to expects' from the area. Additionally, if you're able to make it down to Monterey, place a post on here looking for a buddy, and, contact local dive shop(s).
1) Monterey Bay Dive Center:
http://www.montereyscubadiving.com/
2) Manta Ray Dive Center:
http://www.mantaraydive.com/
Both shops have excellent reputations, knowledgeable staff, good inventory, air, etc. AND, both shops are VERY close to the San Carlos Beach, Monterey -- a few hundred feet, literally.
Anyway, I hope this is a good start. If you have more questions, please feel free to send a PM.
Cheers, Jeff