Hallo
Joomla has one of the easiest installation process.Would suggest you get your hands on xampp or wamp to install for you apache,mysql and php on a windows machine the first time round if your nw too it.
Just need it on your http file on your apache server e.g. C:\wamp\httpdocs\{joomlafile} or C:\xampp\httpdocs\{joomlafile}
call on your machine http:\\localhost\{joomlafile}
And  the installation will run you through the installation process.
Dont forget to remove your installation file before running the actual site.
To login in as administrator http:\\localhost\{joomlafile}\administrator

http://www.youtube.com/watch?v=ei3yPfcxxVc

http://joomlatp.com/joomla-1.5-tutorials/install-joomla-on-windows-+-XAMPP.html