Two strokes don't take well to nitrous oxide, largely due to the ridiculous amounts of heat generated. I mean, it's ridiculous WITHOUT nitrous, but with? You're talking serious engine seize time.
Before I begin...where does my know-how come from? Research...lots of it. I could be wrong on some parts, but I think it's pretty thorough as a guideline. I've never done this, but this should give you an idea of what it would require to do it properly.
That being said, it's totally an awesome ass science experiment, if you have lots of money and/or spare parts. Just don't expect to do any more than drag racing before needing a whole engine overhaul.
You need a WET system - this means that when you flick the switch to engage the nitrous solenoids spray into the engine, a separate FUEL solenoid also sprays gas (and oil in the case of a two stroke) into the cylinder at the same time as the nitrous. A lot of kits sold are dry systems, which suck and will net you very little power and destroy your motor (well, destroy it quicker than with a wet system)
If you don't add fuel at the same time, I can guarantee you will seize within seconds, likely destroying your engines top end, possibly the bottom end as well.
To operate fuel/nitrous solenoids, you need to have an electrical circuit running to them along with all the necessary controls rigged up. This could be power from your bike or a dedicated battery pack - either way, it's not going to be a straight forward operation in any way...you can't just bolt up and go...there's going to be drilling, jetting, running wires, etc, You need to know what you are doing in terms of fuel/air/nitrous mixture BEFORE you test fire it - unless you like spending $100 on parts every time you test a new configuration.
With a 'perfectly' engineered set up where you have taken the time and consideration to provide adequate fuel and lubrication when the nitrous hits (along with a SOLID motor build) - you might get 3 or 4 hard runs out of the bike before you have to replace the piston rings, possibly re-hone the cylinder and rebuild.
Is it worth it for the power? No. Is it worth it for the fun? Probably, if money is no object to you :)