Setting up DNS for web server

[KnightVoyager]

I'm trying to set up a new website on a server I've been working with for a bit now, but although the current sites work fine, the two I'm trying to add just won't go. I have set up the IIS according to directions, and set up the forward/reverse DNS entries pointing the domain to the IP I've assigned to it, but to no avail. I've changed IP's hoping that would work, but it didn't. The IP's I've assigned to the sites are free and should work, but I can't FTP or even browse to them. I'm betting there's something simple I'm missing, but I'm at a loss to know what it is.

Please help!