Jan Haspeslagh asks for the 3 or so titles that best answer this question:
'What literature (journals, books,...) do I have to look for, to keep track
of all newly described mollusk species?' Good question.

Well, Jan, I would include the Mollusca volume of the Zoological Record. The
volumes tend to be printed a couple of years later than the year they
describe, but the bibliography, lists of new taxa, and indexes by author and
subject are rich in obscure references. The parent organization, Biosis,
posts recent information from the Zoological Record on the Web, but for full
access one must subscribe to the service.

The Conchologists of America website has a list of new species at this URL:
http://coa.acnatsci.org/conchnet/edunew-m.html
Like the Zoological Record, it is not fully up to date.

Any other ideas?

Andrew K. Rindsberg
Geological Survey of Alabama