I am trying to figure out a way to ensure that when a user visits my site, they will be presented with a terms and conditions document.

I first thought of putting a large font link to it on my index page along with a fine print link at the bottom of each page. But its very important that the new visitors read the terms and services agreement so as to cover my rear.

So I decided that a popup window similar to the one here on sitepoint when first visiting the site...
That combined with the small font link at the bottom of each page would ensure that each visitor was prompted with the terms of service agreement (at least once heh).

How can i present this popup window to each and every new visitor, but not pest the regular visitors with it each time they come?

I have never made or worked with cookies...
is it something that requires PHP knowledge?
Can this be done with Javascript?

Any information to point me in the right direction would be greatly appreciated... Thanks