Where are you located? I used to live on Silver Bay, which connects to Barnegat Bay about half way between the Seaside Bridge and Mantaloking Bridge. I grew up fishing and sailing the waters of Barnegat Bay and know them really well.
I would take a look at the Toms River, just south of the Seaside Bridge. I am talking about the actual river and not the town (which is to the North and West) There are a lot of sailboat friendly marinas on the river, and some sailing clubs. Go out there any weekend in the summer and you can find hundreds of kids sailing racing small dinghies. I had a power boat then, and while I didn't keep it at a marina, I had all my work done at Marty's Marina. I highly recomend them. Marty and his kids are great guys who really know what their doing. Cozy Cove Marina is there as well. If I were you, I would take a look at the Marinas in Island Heights, on the north shore of the Toms River. There are some on the south shore as well (I think the town is Beechwood but am not sure).
Mantaloking has a yacht club as well, but I don't know much about their marina. Also there are is a marina near the entrance to the Point Pleasant Canal which seems to have a fair share of sailboats, but would require you to go through 2 bridges to get to the parts of BB most suitable for sailing.
If you have any other questions send me a PM.
Also if you are new to Barnegat Bay, be VERY VERY careful around Barnegat Inlet. Strong currents, narrow channels, and shifting tides can make for an unpleasant experience if you are not careful.