Nitrous gurus

As long as you have enough pump you should be fine.

I second the fuel pressure thing. I've always used a small pressure guage mounted in the driver's line of sight, and mount it so that your operating pressure is at 12 o'clock. That way if it suddenly drops, you can back out of it asap to avoid any problems.

I've never been a fan of dropping the timing back. If you do that, the motor is dependant on nitrous to make power because even a couple degrees less timing really kills the low end. I'd be more in favor of dialing the nitrous back a touch and running all the timing you can get away with. If you're running one of those setups that automatically retard the timing when you're on the bottle, then it's much better. As for colder plugs, use your own judgement after a hard nitrous pass. If you find specks on the plugs by all means go colder. One disadvantage of cold plugs on the street is it magnifies any carb problems that may have been "hidden" by warmer plugs. But at the strip where you're running WFO, you should be fine. One more thing I've found: hopefully you're running a regulator to your fuel side solenoids as well as an electric pump. If so, there's lots of fine tuning to be had with a regulator. If it's too fat (rich) drop the pressure a pound and run it again. If it seems lean, go up a pound and so on. If the car seems sluggish, always add fuel pressure first, it's safer. If after going up on your fuel pressure you slow down, then go the other way and see how it looks. Nitrous is lots of fun, but make sure you take lots of notes and only make one change at a time and you'll be fine.