I am creating a site which is basically like an RSS reader, a stream of information from multiple sources.

I would like to display advertising in place of every tenth item (for example). The problem is that I've never done advertising before and am not sure where to look.

I'm not sure that Google Adsense will work in this scenario because it relies (I assume) on a publicly visible page which it can use to determine the relevant content to display in the ad.

What are my options in this scenario?

The site is specifically photography related so is there somewhere I can simply provide some tags and get access to ads to display on my site?