Target a specific <div>

Target a specific <div>

Hey guys, thanks for reading!

I'm in the midst of some volunteer work for my local roleplaying community, creating their website. I want to use a menu bar in the top with a <ul> and simple "a href"'s to switch between the main content. The content of each 'page' will be retrieved from a phpBB board using php.

I've chosen jQuery because I want to learn more about it and have stumpled upon this problem:
How do I target a div, show that, and then hide the current one (or simply all other divs with a certain class). Maybe it has to be done the other way around, hide and then show, to prevent the page from being displayed in a weird way while they're swapping place.

If possible, I would also like to only load the content of the content divs when the menu button is clicked, so it doesn't take load time at first.

Thanks again for reading, any help is appreciated!

Yours
Makey