-Would like recommendations for adding a simple slideshow/picture reel/
Look at jQuery Cycle2, Cycle2 Demos.
on getting the box to slide in and out when choosing a new menu item
I don't recommend building your site that way. I'm not a big fan of 1-page sites. If JavaScript is turned off, menus won't do anything, content will not display. Approx 5% of users have no scripts for perceived security reasons. This could pose big usability issues. I think it's best to build your site with separate web pages instead of 1 long AJAX/JSON driven page. You get more traction from search engines if you have multiple web pages with unique page titles. And search engines drive traffic to web sites.
You PM'd me about different background images. This can easily be accomplished by using embedded CSS code on your internal site pages and changing the background property to a use a different URL.
<style>
body {
background: url(your_new_BG.jpg);
}
</style>
Would like to know how to break the text up into columns within the content boxes
CSS Columns explained:
http://css-tricks.com/almanac/properties/c/columns/
Nancy O.