MySQL data types best practices
Database design : what is the best data type should I use for different sorts of data?
you got to check this links;
http://www.slideshare.net/ronaldbradford/top-20-design-tips-for-mysql-data-architects-presentation
http://www.wsi-ebizsolutions.biz/blog/optimal-mysql-data-types/2010/01/
http://www.developwebsites.net/choose-optimal-mysql-data-type/
http://help.scibit.com/Mascon/masconMySQL_Field_Types.html
http://articles.techrepublic.com.com/5100-10878_11-5980073.html