A Simple Move… Or Is It…

Hi, i am in the middle of coding a wordpress site for my client. The client already has a site and wants to keep the old site running until the new site is ready to go live.

I am currently setting up the new site on http://www.theoldsite.com/d3mo/ and then i plan to move it to the live home directory when the content has been added.

MY QUESTION
– what additional steps do i need to do other than just copying all of the files in the /d3m0/ to the http://www.theoldsite.com/ directory… do i need to set up wordpress in any special way or change permalinks or any other links… will stuff stop working when i move it to the live directory, thanks in advance