How to Show WordPress Posts from a Single Category Only

Hey Friends use this plugin its solve all your problem related to this topic –

http://wordpress.org/plugins/ultimate-category-excluder/

Ultimate Category Excluder, abbreviated as UCE, is a WordPress plugin that allows you to quickly and easily exclude categories from your front page, archives, feeds, and searches. Just select which categories you want to be excluded, and UCE does all the work for you!

show latest post on homepage with select category in wordpress