when did you get your camera? i meant how old is it? is it actually a video camera? or just a digital with video abilities?
if your camera is fairly new and is made for recording videos, the sound quality should be acceptable. if it is a digital camera meant for photography, not videos, then the sound quality is probably not so good. also, if you have the manual still you should be able to find out how to use the video function. since you dont know how to, im assuming it isnt a camcorder.
as for software, i dunno what you can use other than what i use. you probably wont need much editing, though, for this purpose.