I can't get the whitespace below the header to go away. I'm new at WordPress but have done websites. I tried the FAQ answer and the CSSs Insert now read:

td#header {
padding-bottom: 0px;
}

But the space is still there. Website home page

I also looked at #imagecontainer and class="header-image-container", and looked for class="clickable" and class="divclick", but couldn't find them via WordPress admin. FTP access is supposedly coming soon, but I don't have it at the moment.

what height did you specify your header image is in the options?

Did you try negative margins on any of those elements?

It was 150 and the default is 150 and the image was 150, but after reading your comment and the hints in the admin, I reset it to 144, which seems to have solved my problem (as I see lmilesw suggests below).

Thanks!