Need help to identify Costa rica Pacific shell....beginner issue

[Argonauta]

I need to identify some shell I found on the waters of the South pacific coast of Costa Rica.
I am a beginner, and I need to know which book or catalog could help me to identify shells of my area.
Thanks a lot for the help.
the shell I need to identify are the following ones :

<!-- m --><a class="postlink" href="http://www.badongo.com/pic/13028392">http://www.badongo.com/pic/13028392</a><!-- m -->
<!-- m --><a class="postlink" href="http://www.badongo.com/pic/13028393">http://www.badongo.com/pic/13028393</a><!-- m -->
<!-- m --><a class="postlink" href="http://www.badongo.com/pic/13028394">http://www.badongo.com/pic/13028394</a><!-- m -->
<!-- m --><a class="postlink" href="http://www.badongo.com/pic/13028395">http://www.badongo.com/pic/13028395</a><!-- m -->
<!-- m --><a class="postlink" href="http://www.badongo.com/pic/13028402">http://www.badongo.com/pic/13028402</a><!-- m -->
<!-- m --><a class="postlink" href="http://www.badongo.com/pic/13028411">http://www.badongo.com/pic/13028411</a><!-- m -->
<!-- m --><a class="postlink" href="http://www.badongo.com/pic/13028412">http://www.badongo.com/pic/13028412</a><!-- m -->
<!-- m --><a class="postlink" href="http://www.badongo.com/pic/13028435">http://www.badongo.com/pic/13028435</a><!-- m -->
<!-- m --><a class="postlink" href="http://www.badongo.com/pic/13028440">http://www.badongo.com/pic/13028440</a><!-- m -->
<!-- m --><a class="postlink" href="http://www.badongo.com/pic/13028442">http://www.badongo.com/pic/13028442</a><!-- m -->
<!-- m --><a class="postlink" href="http://www.badongo.com/pic/13028443">http://www.badongo.com/pic/13028443</a><!-- m -->
<!-- m --><a class="postlink" href="http://www.badongo.com/pic/13028447">http://www.badongo.com/pic/13028447</a><!-- m -->
<!-- m --><a class="postlink" href="http://www.badongo.com/pic/13028448">http://www.badongo.com/pic/13028448</a><!-- m -->
<!-- m --><a class="postlink" href="http://www.badongo.com/pic/13028449">http://www.badongo.com/pic/13028449</a><!-- m -->
<!-- m --><a class="postlink" href="http://www.badongo.com/pic/13028450">http://www.badongo.com/pic/13028450</a><!-- m -->
<!-- m --><a class="postlink" href="http://www.badongo.com/pic/13028454">http://www.badongo.com/pic/13028454</a><!-- m -->
<!-- m --><a class="postlink" href="http://www.badongo.com/pic/13028455">http://www.badongo.com/pic/13028455</a><!-- m -->
<!-- m --><a class="postlink" href="http://www.badongo.com/pic/13028460">http://www.badongo.com/pic/13028460</a><!-- m -->
<!-- m --><a class="postlink" href="http://www.badongo.com/pic/13028464">http://www.badongo.com/pic/13028464</a><!-- m -->


thanks a lot for the help