Does anyone have any recommendations for a nice bed and breakfast along the Jersey shore, accessible by train from NYC (I don't want to have to rent a car). I'd like to have a relaxing/fun weekend get-away mid-April and would like to stay near the ocean.

I think you will like Spring Lake. Take the New Jersey Transit Coast line out of Penn Station (change trains in Long Branch).
I've never stayed at these but here are some B&B's there.
Ashing cottage 732-449-3553
Johnson House 732-449-1860
Normandy Inn 732-449-7172
Sea Crest by the Sea 732-449-9031
Victoria House 732-974-1882

Thanks, SusieQQ. I'll check these B&Bs out!

Bay Head is another good choice as you can take a train right there. The hotel noted below is within walking distance of the Bay Head train station; however I can't guarantee that they are open in mid-April, which is very early in the season, not beach weather unless you get an unusually warm weekend.
Bay Head Gables Inn
200 Main Avenue
Bay Head NJ
732-892-9844
http://www.bayheadgables.com/


Spring Lake has one ocean front B&B:
The Breakers
1507 Ocean Avenue
Spring Lake
Phone: (732) 449-7700 ~ Fax: (732) 449-0161
breakershotel.com

The hotel is actually across the street from the ocean.

website for Bay Head is bayhead.org

Website for Spring Lake is springlake.org

If you are looking for a great water view, but don?t need a beach, try the Ritz-Carlton Battery Park in Manhattan. It is down near the WTC and most rooms have great views over the harbour and the Verazzano bridge. They have a spa and fitness center. The rooms have the big bathrooms you are looking for, plus room service?.They usually offer good weekend rates.

The Ritz-Carlton New York, Battery Park
Two West Street
New York, New York 10004
Telephone: (212) 344-0800
Facsimile: (212) 344-3804
www.ritzcarlton.com/hotels/new_york_battery_park

Just one note: The Breakers in Spring Lake is not a B&B. It is a hotel.