all depends. Most times smart ripper & DVD decrypter rip the subtitles along with everything else. The subtitles info is in the IFO file (usually looks like this: vts_01_0.ifo).
So all you need to worry about now is the app you will use to encode with to support the subtitles you want.
What type of file do you want to make? DivX, VCD, SVCD?
Different tools for these different types to help with subtitles.