Sarah,
 
I won't touch the common name subject as that is a very, very dead horse
that was beaten severely on Conch-L about 6 months ago.  Like all who
get into shells, if you are half way serious you will fast come to rely
on scientific names, BUT that doesn't take away the enjoyment of common,
often local and full of fun and meaning, names.  And that is how to hit a
dead horse even after promising not to.
 
About shell books on the Caribbean.  I recommend "Seashell Treasures of
the Caribbean," by Lesley Sutty (ed. by R. Tucker Abbott), pub. by
E.P.Dutton, NY, New York, 1986.  This is a good read cover to cover with
magnificent photographs and some very interesting shell information.  It
only covers about 100 shells but the presentation is superb.
 
A little deeper into shells (again not a species list) would be "A
Natural History of Shells," by Geerat J. Vermeij, pub by Princeton
University Press, 1993.  This is not on Caribbean shells but it has some
fascinating stuff on how shells came to be as they are, how shells work
for the animal, etc...  Kind of a how, what, why, when, and results for
shells.  A little heavier than the Sutty book but really some incredible
information.
 
There are a lot of other books on shell lore and general shell knowledge
(look at a used book store for "Kingdom of the Seashell," by R. Tucker
Abbott - lots of shell lore).
 
Good luck on your shell knowledge quest.  If you keep at it you will
eventually find thousands of monographs and papers on different shells or
aspects of shells.  A member of our local shell club has over 6,000
books, magazines, monographs, reprints, and xerox copies of shell papers
(although most of his are on fossil shells).
 
Tom Eichhorst
 
P.S.  When you get stuck on something shell related there is ALWAYS
someone on Conch-L who can help out.  These are a great bunch of folks.