I was searching for subtitles as well, a couple of months ago... Unfortunately, you'll have hard time finding subs for even 3-4 episodes. To be honest, only thing I found was SRT Subs for some of the movies. I would suggest either watching Pocket Monsters/Pocket Monsters Advanced Generation without subtitles. I believe they are not the most difficult Anime on meaning. Just with the pictures and some basic, not without even a word of Japanese you can have the basic meaning of the episodes.