If Mario wants to use Blender, don't discourage him. If you don't know how either, tell him you don't know, or don't post at all.
If you simply look at Blender and think, "wtf?" and quit, you're not going to learn anything. Watch/read tutorials. That pretty much how you'd learn Milkshape as well.
Before you ask, yes, I have used Milkshape, and I think its far too basic.
There's some good tutorials at
www.blender.org.
You'll also need the DTS exporter, and knowledge of how to use it. I'm too busy to give a direct link, so just search one
www.garagegames.com