Offshore fishing in New England

Hello, I am new to this group and I can't figure out why I didn't check it
out earlier. This looks like a great place and I look forward to learning
more.
I am in charge of scheduling an offshore charter for 6 guys next summer
(05). I was wondering if any of you have experience with the many charter
boats along the Mass. coast. I am considering going with Big Fish in
Marshfield, they go out to the Stellwagen Bank and July seems to be a good
time for cod and the various other fish they catch out there.
I guess what I'm "fishing" for is what I should expect and any tips I might
not consider before going.
Thanks in advance for any advise you might be able to give.

chris