Convert movie to fit on pda with subtitles?

I am so new here I hope I am putting this in the right spot. If not I am very sorry, I have never used a forum before.

I am trying to shrink a movie so I can put it on a 1gb memory card but have it play the english subtitles to.
I just cannot figure out how to get the subs in it.

If anyone can help…Thank you very much.