How to set up environment for module development

Hi.

I would like to start module development  but I am slightly confused about the installation process. I have already downloaded and installed the DNN Platform onto my local computer without issue. I got the download from here...

http://dotnetnuke.codeplex.com/

...which was a zip file called DNN_Platform_07.02.00_Install

I looked up how to start module development and am now following this tutorial...

http://www.dnnsoftware.com/Community/Learn/Video-Library/View-Video/Video/437/View/Details/DotNetNuke-Explained-Basic-Module-Development

...and I got to this link...

http://bit.ly/moduledev

...which took me here...

http://www.dnnsoftware.com/community-blog/cid/134662/Getting-ready-for-DotNetNuke-Module-Development

...then clicked the DotNetNuke Wiki about Setting Up Your Development Environment link which took me here...

http://www.dnnsoftware.com/wiki/Page/development-environment

...and I got as far as the INSTALLATION CONFIGURATION and the DOWNLOAD section. I click on download and it takes me to here...

http://www.dnnsoftware.com/Platform/Start/Extend

...so, what do I do from here? There is nothing to download?

Thanks for your time with this.