In most cases when creating a site in Joomla!, the first choise on the menu is something like "Start" or "Home" that brings the user back to the landing page of the site. Normally you will also link the website logo to the start page.
But sometimes when creating a site in Joomla, it is not desirable to have a specific menu item with the sole purpose to bring up the start page. Just linking the logo to the start page may be sufficient and you don’t want to clutter up your menu with an additional item (or you are running out of menu space).
The solution to not having a menu item corresponding to the start page is to simply create a hidden menu, for example "hiddenmenu". Do not publish a module for it. Place the menu item that brings up the start page in this hidden menu. Done!
By the way, linking your logo to the start page can be done in the template html-file by something like this:
<a href="<?php echo $this->baseurl; ?>"><div id="logo"></div></a>