Find "Music"
Press Applications.
Press Music.
Create playlist
Press Playlists.
Press the Menu key.
Press Create.
Key in a name for the playlist and press Save.
Add audio files to playlist
Press Add music.
Press the required audio files to tick them.
When the box next to an audio file is ticked (V), it's selected.
Press Add.
Exit
Press the Home key to return to standby mode.