[Koha] Koha and display of diacritics/non-Roman alphabets/characters

I am brand new to Koha, but having a good time learning about it. I have encountered a stumper, however. Can someone explain how to set up the system to properly display diacritics and non-Roman characters? For example, I have a book about the Soviet Union that is written in French, and it is not rendering either the French or the Russian diacritics. I also have materials in Asian languages such as Lao and Thai in the catalog. Thanks for any tips. Bruce Willms East Side Freedom Library St. Paul, Minnesota