The best single
listing of cruising, weather and shortwave broadcast stations that I know of is:
The above site marks both Marine SSB
and Ham nets.
If you are a Ham, you can transmit and contact the Maritime Mobile Service
Net on 14.300MHz. It is the single
best net out there, for a cruising sailor.
If you are not a Ham, you should get in contact with a club, get the books
from ARRL, study and become one as soon as you can. It is very very worthwhile and will open up a world of resources to you when you are out there. You can become a General ham in a month, or two. I can honestly say that becoming a ham was one of the best things I ever did for myself.
Best of luck