This Instructable is layed out assuming that you know jack-didly about knife throwing.
You may ask yourself, "Why do I need to learn to throw knives?"
Well that's a good question, but the answere is even better...
What if the fall of western civilization knocks on your door tommorrow?
What if zombies.... Okay I'm just joking. (But it could happen ;) )
A good reason to take the time to learn this art is simply because it's fun. Remember when you were a kid learning to play poker for the first time? What about chess? Any game like that really. Why do we play those games? How do they intertain us?
They're a challange. It makes you think about what you're doing, what you want to happen, and why it did or did not happen.
Not to mention that you'll be able to cleave razor sharp shinny things through the air when you're done. (And actually hit what you where aiming at)
Step 1: Picking a knife to throw
There are thousands upon thousands of commercially available throwing knives out there. Different styles are plentiful; some are great, some are useless. "Leaf Throwers" are among my favorites, their characteristic "Leaf" shaped symmetrical blade is where there name comes from. There are also some more trditionally shaped single edged knives, and nonsymmetrical double edged knives like the "Hibben Pro 2" and it's copies, there's even a totally bizare "Torpedo" which is a round double pointed throwing rod, and many more. There are also knives with positionable weights on the handle and blade, personally I think these are usless.
You can technically throw any knife with a suitable ballance point. Knives with bulky handles are a bad idea, and you generally want to stay away from folders, due to there handles they can be very inaccurate and they tend to ballance funny.
For this Instructable, I did however pick a folder, so it can be done. But I suggest against it for someone new to throwing.
In fact a Leaf Thrower is what I'd suggest you start learning with.
Here are some of the knives I discrbed...