If you have multi byte data in your tables its important to take backup in utf8 which can be done using the command below:
mysqldump -u root --default-character-set=utf8 DB_NAME | gzip > DB_NAME-`date +%Y%m%d%H%M`.sql.gz
The date parameter simply appends date/time to the backup.
In order to restore the backup taken above use following command
gunzip < FILE_NAME.sql.gz | mysql --default-character-set=utf8 -u root DB_NAME
This will ensure that db is back up without affecting multi byte data.