Sorry to bother with this and highlight myself as a complete HTML/CSS noob, but I am not sure how to add a banner image to my Zenphoto gallery. I am using the Default Theme with the Dark style, and I tried looking through index.php to see where to easily add it, but I either have my HTML code snippet wrong, or I am putting it in the wrong place. Any help would be appreciated! Thanks.

Of course you realize that this is not the place to be taught the absolute basics of HTML/CSS.
The web is packed with tutorials.

Yes, I do understand that.
I was hoping that someone else had done some work on the default them and could point me in the right direction. I have done some modifications to my Wordpress blogs, which mainly involved changing the header attribute in the CSS and PHP files, but I do not see similar sections within the files for the Zenphoto Default Theme. I was thinking I may need to add a Header section to the CSS and any subsequent PHP files I want changed, since there is not one currently. But before undergoing that process, and possibly wasting more time on a non-solution, I was hoping some could either confirm that or point me in the actual right direction. I don't need or want a full HTML/CSS tutorial right now.

The only way to get a kind of header image into the default theme without changing the HTML is probably changing the CSS. The CSS id "gallerytitle" in that theme is what comes nearest to a "header". You could attach a background image for example.

In any case you will have to do some work until it fits your needs. GEnerally Zenphoto themes do not require any standard HTML structure within their theme files (there is basically one but you can do whatever you like actually).

Ok awesome! Thank you very much for your help, I will play around with that a little and work it out.

I spent a few hours working on everything and was able to get a banner setup for all the pages as well as some other modifications to make the layout more aesthetically pleasing to me. I should probably do some more changes later to bring it more in line with the rest of my site, but I need to some homework, lol. Anyhow thank you for your help and for all the awesome work on Zenphoto, I am loving it so far! Feel free to check out my site and let me know what you think :) (www.liechswonder.com/photography)