MACT

Captitles has a free program to help you create open captions for your production. Here are some tips from them on how to properly divide captions, set the right font size and style, use context cues, comply with recommended length, and positioning and timing conventions. Click here to read the article.

And for a change of pace they also have an article on how NOT to prepare subtitles. This article is a good introduction into planning for using subtitles. Click here for this article.