The best software out there that I found was Adobe Premier - I'm not sure of costs but it is professional grade stuff. You can do anything with this software. The video's I've made don't even scratch the surface of Premier. They're might be a 'lite' version available.
Since switching to linux a few years ago, I use Cinelerra - also very powerful AND it's opensource.
They do make a Windows version so you might like to google that.
It does multi track both video and audio, encoding is fully supported as to what codec's you have installed on your system.
There are also plenty tutorial video's on youtube for this software, as if you're not used to Premier, it can be akin to being thrown in the deep end.
You might also want to look at ffmpeg for DVD burning - extremely powerful too.
hth
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