My host creates a "free" address which works like this: mysite.com and myhost.mydirectory.com = the same page It's like my whole site has a complete double with this seperate subdomain address.. Will this affect Google, seems how there are 2 address leading to the same content? Thanks
If you redirect one of domains to another one using 301 redirect it will be OK and you will not faced any problem with Google. For redirecting your domain, if you have Cpanel on your server go to 'manage redirects' and manage one of them to the other one using 301 redirect.
place <link rel="canonical" href="http://www.mytruedomain.com" /> in the <head> section of the hosts duplicate page