OK. The Venom 1000 system only activates if three things ocurr:
1 - You must be at WOT based on a signal from your TPS.
2 - The signal from you 02 sensor must not show that you are running lean.
3 - The system must be turned on.
Also, if you add a window switch (which I recomended) the Nitrous will only spray if you are within a pre-determined RPM range. The important part here is that a window switch prevents nitrous from spraying if you were to hit your rev limiter.
The cheapest place to get the system is from Boro Performance. Their phone number is: 888-974-2133. It sells for $560 shipped from them. If you call, tell them you called in March and were quoted $525. They were running a sale then. Maybe they would let it go at the lower price for you if you ask.
BTW, I don't have one but I am going to get one. I have researched N02 quite a bit and spoke with about 6 guys who are using the Venom. No complaints. Great, safe, system for a beginner.