Backing Up and Restoring Your MySQL Database

You can find more details on following links

http://www.devshed.com/c/a/MySQL/Backing-up-and-restoring-your-MySQL-Database/1/
http://www.mysqlperformanceblog.com/2006/07/30/mysql-crash-recovery/
http://dev.mysql.com/tech-resources/articles/recovering-from-crashes.html.
http://bytes.com/topic/mysql/answers/631163-how-change-mysql-database-directory