I am working on this site...

http://www.lauralewismantellmd.com/index3C.html

In IE it shows exactly as I want it to in terms of the distance between the graphical montage and the navigation line. In FF, it is way too close. If I program it to look the way I want to in FF, it is way to big in IE. Any thoughts on how to get them to look more similar in both? TIA!

Try adding utf-8 character encoding.

I find browser margin/padding differences to be quite irritating so more often than not I set them all to 0 at the top of my sitewide stylesheet

* { margin: 0; padding: 0; }

It looks too close in FF because the div "charta" stops short of the bottom of the images, not effectively 'containing' the images.

Clear the floats of your list right after the </ul> for nav, that solves the problem.