In the Launchpad Customization section you will be able to upload images for logos and backgrounds for the Signup and Launchpad pages. You can also set a custom favicon (the icon shown in the browser tab where the Launchpad is running). You can also set:

a custom Launchpad logo URL (e.g. link to your home page),
a custom Launchpad page title,
a custom HTML footer for the Launchpad and Sign in page,
a custom link color (for the "Resume" and "Power Off" links shown in the Launchpad when there is an active session),