Splash pages (those annoying pages with some sort of fancy graphic or flash intro that say "Click to Enter" or "Skip Intro") are bad. I could spend a whole article trying to convince you of this fact, but I think this article does a better job of it than I could ever do.
One of the most common mistakes made by Joomla! designers is to assume that just because you loaded Joomla! in a directory called "http://www.yourdomain.com/joomla" or "http://www.yourdomain.com/cms" or "http://www.yourdomain.com/home" rather than your root web directory, you are stuck needing to create a splash or intro page in your root directory to point your users to the real site. Nothing could be futher from the truth. As a webmaster, you have a couple of options for pointing users to your content without the need for a splash page. I will try to cover those options in this tutorial.