How can I display separate taskbar for each form ?
To do this, you must override the CreateParams method in each form.. you see, visual inheritance is a good practice here :-)

unit Unit1;

interface

uses
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
StdCtrls;

type
TForm1 = class(TForm)
Button1: TButton;
procedure Button1Click(Sender: TObject);
private
{ Private declarations }
public
procedure CreateParams(var Params: TCreateParams); override;
end;

var
Form1: TForm1;

implementation

{$R *.DFM}

procedure TForm1.CreateParams(var Params: TCreateParams);
begin
inherited CreateParams( Params );
Params.WndParent := 0;
end;

end.