This is as basic as it gets; bear with me please. Okay, so when Google sends me the ads, I can place them on any page in my site? I don't have to place them on every page, such as the index page. Is that correct?

Also, as far as I can tell, it seems like the implementation would be similar to using a java applet or an image or whatever-- you just place it in the html wherever you want? So, in other words, to make it easier to fit into my pages that are already made, I could just add another table to the html containing the code for the ads? Thanks.

Okay, here's another.

I want to use a seperate two-row table above the fold. In the top row would be four generally relevant images (astronomy equipment and astrophotography is the subject.) How often will these text ads change? Will I be able to switch the images to make each one even more relevant to the text ad beneath it?

Thanks again.