System

$ echo $LANG
hr_HR.UTF-8

Apache

httpd.conf:

 AddCharset UTF-8 .utf8
 AddDefaultCharset   UTF-8

MySQL

Edit /etc/mysql/my.cnf under the [mysqld] section:

 init-connect = 'SET NAMES utf8'
 character-set-server=utf8
 collation-server=utf8_general_ci
 character_set_client=utf8

show variables where variable_name LIKE "character_set%" OR  variable_name LIKE "collation%";

 | character_set_client            | utf8                                                     |
 | character_set_connection        | utf8                                                     |
 | character_set_database          | utf8                                                     |
 | character_set_results           | utf8                                                     |
 | character_set_server            | utf8                                                     |
 | character_set_system            | utf8                                                     |
 | character_sets_dir              | /usr/share/mysql/charsets/                               |
 | collation_connection            | utf8_general_ci                                          |
 | collation_database              | utf8_general_ci                                          |
 | collation_server                | utf8_general_ci    

Encoding and Character Sets in Koha (Koha wiki)
http://wiki.koha.org/doku.php?id=encodingscratchpad

See also: Sorting Croatian characters in MySQL