It depends on what you want the shape of the sword to be, and how many polys you want it to be. If you want to create a simple sword such as a strait edge katana a cube would be a good starting point. Next you would scale the cube so that it was the approximate shape of the blade. An extrusion would be used on the tip. Then you weld any verts that are on the blade side. All of this depends on what type of sword.
If it were a curved sword it would be much faster to trace a polygon over the shape of the sword (with a low poly count in mind) and then extrude and weld for the blade.
as for the handle and tsuba those are just cylinders.
Goto http://www.shellshockede.com