When you first open Floodlight, you'll see a default playlist with a helpful message encouraging you to read this manual. In the "Playlist" pane on the left, right click the "Welcome to Floodlight!" segment and click "Remove". You now have an empty playlist.
Empty playlists are boring, though, so let's add something else. Just under the Playlist pane is your Library. Right click the empty area and choose "Add->Import...". Find an image or video on your computer and click "Open" to add it to your library. Then, drag it from your Library to the Playlist above. You'll now see a single slide on the right. Click on it to show the image on the screen.
Of course, you'll want to add songs to your playlist, not just media. There are several ways to add songs to your Library.
Copy and Paste
You can easily copy and paste lyrics into Floodlight. First, copy the lyrics you want to import. Then, right click the Library pane and go to Add->Paste Lyrics. A new song will be created, and a tab will be opened so you can edit it.
You can add a song manually. Right click the Library pane and go to "Add->Song". This will open the Song Editor tab. Refer to Editing Lyrics to add lyrics to your new song.
Headers can help organize your playlist into parts, such as Pre-Service, Service, and Post-Service. Right click the segment you want to add a header above and choose "Add Header". Then type a name for the header and press Enter.