http://www.square-enix-usa.com/seui/index.htm You'll have to register first, but it's free. Then choose FFX-2. Also don't forget to choose optional missions if you do use this. (I didn't use this, but I know some people have been asking about a guide.)
www.gamefaqs.com also has one.
The Samurai D.S. is on the floor in Kilika in Ch.3, just before the door to the fayth.
Paine's Special you have to speak to Tromell 4 times in either ch.1 or ch.2.
