Permissions on /var/www/html for uploading web site files via SFTP

Hi,

I’ve installed nginx successfully on an Ubuntu instance here at DigitalOcean. The index.html page (in /var/www/html) displays appropriately: “Welcome to nginx on Debian.”

Now I want to upload some files via Cyberduck (sftp) to “duplicate” my current web site currently hosted elsewhere: chestradiologists.org

But I cannot because I don’t have the appropriate permissions. (I created a new user with sudo permissions after I created the Ubuntu VPS.)

Via Cyberduck, I see the following for /var/www/html (all these directories):

rwxr-xr-x (755)

        Read      Write     Execute

Owner Y Y Y Group Y No Y Others Y No Y

Owner 0 Group 0

…

I’m the only user that will upload files I create with Octopress on my Mac.

How do I change the ownership/permissions to best accomplish this ?

I have a rudimentary understanding of Unix permissions :-(

So, please explain with some detail if possible.

Thanks!