How to configure global charset on MySQL

I tried to change the charset for our MySQL via my.cnf and it failed. I added the charset settings listed below:

# The MySQL server
[mysqld]
port            = 3306
socket          = /var/lib/mysql/mysql.sock
skip-locking
key_buffer = 16M
max_allowed_packet = 1M
table_cache = 64
sort_buffer_size = 512K
net_buffer_length = 8K
read_buffer_size = 256K
read_rnd_buffer_size = 512K
myisam_sort_buffer_size = 8M

# ------------- MYSQL CHARSETS --------------
character_set_system = utf8
character_set_server = utf8
character_set_results = utf8
character_set_database = utf8
character_set_connection = utf8
character_set_client = utf8

collation_connection = utf8_general_ci
collation_database = utf8_general_ci
collation_server = utf8_general_ci

When I had these enabled, MySQL failed to start. How can I make sure everything defaults to utf8 - always?

Update

There are still a few places having issues in being UTF8

character_set_client    utf8
character_set_connection    utf8
character_set_database  latin1
character_set_filesystem    binary
character_set_results   utf8
character_set_server    latin1
character_set_system    utf8
character_sets_dir  /usr/share/mysql/charsets/
collation_connection    utf8_general_ci
collation_database  latin1_swedish_ci
collation_server    latin1_swedish_ci

Unfortunately I still haven't come up with a soluton... any ideas?

Currently I'm using this configuration successfully:

[mysqld]
default-character-set = utf8
init-connect='SET NAMES utf8'
character-set-server = utf8

[mysql]
default-character-set = utf8

But PHPMyAdmin is still showing some latin1

```
character_set_client utf8
character_set_connection utf8
character_set_database latin1
character_set_filesystem binary
character_set_results utf8
character_set_server latin1
character_set_system utf8
character_sets_dir /usr/share/mysql/charsets/
collation_connection utf8_general_ci
collation_database latin1_swedish_ci
collation_server latin1_

You need to incorporate the following into your my.cnf file

[client]
default-character-set=utf8

[mysql]
default-character-set=utf8

[mysqld]
default-character-set = utf8    
collation-server = utf8_general_ci
init-connect='SET NAMES utf8'
character-set-server = utf8

You can find more information on the following manual pages

-
http://dev.mysql.com/doc/refman/5.6/en/charset-configuration.html

-
http://dev.mysql.com/doc/refman/5.6/en/server-system-variables.html#sysvar_character_set_system

-
http://dev.mysql.com/doc/refman/5.6/en/server-system-variables.html#sysvar_character_set_server

In response to Mark's answer, if you need to convert existing tables/databases to the correct character set you will need a suitable ALTER query. Something similar to the below:

ALTER TABLE `table` CONVERT TO CHARACTER SET utf8 COLLATE utf8_unicode_ci;

Alternatively there's a great PHP script here which does it for you.

StackExchange Database Administrators Q#8288, answer score: 24