I've got a moderately complicated application that has been developed primarily by me, and I'm getting ready to bring a few more developers in, and I'm thinking of various forms of documentation that might be helpful.

I want to communicate information about the directory structure/layout of the project so the new guys will know where to look for things when they are getting started and as they add features, know where to put new files etc., so we can keep things organized and consistent.

Is there any tool out there can create something a little more sophisticated than just a plain text document? I'm thinking of something that looks similar to Windows Explorer with a directory structure on the left in a panel and then when you click on a particular folder, you would be able to view some text or HTML that describes the folder in the right hand panel.

Oh, and development will be done on Windows, but cross platform would be nice.