I can't think of specific titles to cover, other than those already
mentioned, but many groups have gone to great efforts to prepare such
lists for you. Try getting the latest Index from the Catholic Church, or
the banned list from the Commonwealth of Massachusetts, or call up some
organizations of book-burning enthusiasts, like the PTA of Huntsville, Ala.
The ACLU might have a list of other book-burners for you to contact.
Your customers might appreciate knowing just which sociopolitical groups
are offended by which books you carry, so your catalog ought to include
a handy icon-based code for each title.