how to make a blog

Hi. I gest instal wordpress 3.0 on my root of my site. I’ve made some subdomain on subfolder for my site and then in my wordpress 3.0 cpanel i’ve created some site with the name of my subdomains. In the wordpress 3.0 cpanel when I clic the view site button it takes my to the actual subdomian and I view my site wich I think is ok but I want to know how to make some blogs for each of the subdomains that I created.