Tom Green wrote a great tutorial divided into 2 parts about how to insert captions on your flv. This tutorial is very easy, and very well explained.
Tutorial – Captions for Video with Flash CS3
About the Author: Carlos Pinho
A father, a husband and a geek... Carlos was the founder of projects like The Tech Labs and Flash Enabled Blog. He is the founder of TekTuts He is passionate about technologies. Their main skills are in analytics, transport & logistics, business administration. He also writes about programming resources, trends, strategy and web development.