Dolby Digital Mixing?? Help, Mixing a movie score in Dolby Digital Options

[linkinpark489]

A couple of my buds are going to make an independent film and they have put me in charge of making the score. I am going to write the music myself and record it and all that. They came to me the other day and told me that they were going to burn the finished movie on dvds and they said they would really like the audio and sound in dolby digital 5.1 so it can be played on a 5.1 surround system and all that (i guess they are gonig for as professional as possible). I was wondering how i go about recording and mixing so the final product will be in dolby digital and all that. I am completely new to this topic so any information would help thanks