Before you begin there are some important thing you will need to have:
-Angle grinder (or if you don't have one a hacksaw)
-MIG Welder (this is the most important thing you will need)
-Basic tools (spanners, hammer, sockets, socket drive etc)
-And a lot of space to build the thing!
And remember if you have any questions please dont hesitate to ask.
Step 1: Finding a bike
There's really not a lot I can tell you about this except I chose a 1998 Suzuki Katana AY 50 because it was the only one I could get for free (it wasn't running, but I fixed it). I would recomend a bike like this but really any bike will do, as long as it starts and goes.