hi, i need to produce a dvd with my videos, at this time i just have only the videos witout sound, so, my questions are:

1. what program should i use to join 2 mp3 files in one single?

2. what program should i use to join the video and sound (voices, music) and then produce a new video with the sound added?

3. what program should i use to put this video in a dvd format and create a dvd menu?

regards