As Helmut, David, and Aydin indicated, assuring that what you want to name
is not already named is the first issue that must be addressed.  Naming a
species is a lot of work, and if the research portion of the project is not
done extremely thoroughly, the entire endeavor may well turn out to be a
colossal waste of time and effort, when someone else notices a prior
description of your shell in a journal that you overlooked.  The prospect of
having your name incorporated into the natural history of the earth until
the end of time does have an attractive ring to it, but many who have
explored the possibility of naming a species have had second thoughts once
they discovered the amount of time, labor, and expense that might be
involved.  To properly do the required research, two things are needed -
access to the many journals and other publications in which similar species
were described; and access to study series of the actual specimens, from a
variety of localities.  Of course, such material will a lot more voluminous
if you are naming an Anachis than if you are naming a Struthiolaria, but
still it involves a lot of work, even if you are a professional in an
institution with a large scientific library and in-house study collections.
Even then, no library or study collection will include everything that is
needed, so some travel to other institutions is usually involved.  Most
individuals who are not professionally connected do not have ready access to
the necessary materials.  This means traveling to libraries where the
literature can be found, and spending countless hours studying it.  It means
photographing and xeroxing reams of material.  These days, some of the
literature may be accessible through the internet, but the majority of it is
not.  It means making appointments, often months in advance, with the
museums which own the necessary specimens, to examine the appropriate
portions of their study collections.  Unless you have plenty of free time,
absolute determination, and a bit of spare cash, it's probably better to
approach a professional malacologist about describing your species.  He/she
may just name it after you, and your name will thereby be immortalized.
Paul M.