The question is meaningless as asked. Is it your way of saying you want to give each author a subdirectory (site.com/author1, site.com/author2, etc.) or a subdomain (author1.site.com, author2.site.com, etc.)?
Er, yes what? Do you need subdirectories or subdomains?
If you need subdirectories, all you need to do is to go to Options | Permalinks in your admin interface and create this (or similar) custom permalink structure:
This will give you URLs like
If you need subdomains, you can either create them manually and install a separate copy of WordPress on each subdomain or install a single copy of WordPress MU, which will handle subdomains for you (if your hosting setup allows it, that is).