Well, I can't get the applet to work on an html... only on the applet Viewer on NetBeans. Perhaps there's something wrong with the dir to the resources?

    public static final String Texture_LightPlayerPiece = "/data/marble.jpg";
    public static final String Texture_DarkPlayerPiece = "/data/wood.jpg";

 texMan.addTexture("LightPlayerPiece", new Texture(documentBase, Resources.Texture_LightPlayerPiece));
        texMan.addTexture("DarkPlayerPiece", new Texture(documentBase, Resources.Texture_DarkPlayerPiece));