I have a username and password in www.godaddy.com , but unable to host so how can I do that

You have to purchase a hosting account. Frankly I think godaddy's hosting has much to be desired. I use and recommend Lunarpages (http://www.lunarpages.com)

RickJ, actually all domain's purchased on Godaddy.com include a free hosting (ad-supported) account.

Habesh, here's a helpful link: Getting Started Guide for Your Linux Shared Hosting Account - Help Center—Knowledge Base and FAQ (http://help.godaddy.com/article.php?article_id=1361&topic_id=&prog_id=GoDaddy&isc=)