I created a Force.com site and linked a Visualforce page with it, but when I access the link I get down for maintenance error page. I am not sure how to get my visual force page instead of this error. I made the force.com website as active too but I still this error page. I saw this help link - https://developer.salesforce.com/forums/?id=906F000000099UQIAY
In my experience down for maintenance usually means you have an incorrect URL. make sure that you have found the correct link to the Site.
The link you reference says that the person created a new site sub-domain. Created a new "SiteName" and it seemed to have resolved his error (my guess is that something else was going on).