The best news about the Phantom 2 Vision is that it's sold as RTF (ready to fly) right out of the box. Since we're talking about a $1,200 investment, you would be wise to totally ignore that claim.
You need to assiduously and meticulously adhere to a preflight routine each and every time you take your Phantom out to fly.
1) Make sure you have everything you need, and anything you might need, before leaving the house. (Having an actual checklist makes this a bit easier.)
2) Make sure ALL of your batteries are charged or when appropriate, you have new spares with you.
3) Be SURE your Phantom has located the minimum number of GPS satellites and has locked in on its current position, to make sure that the fail-safe Return To Home feature has a chance of working...
4) Once all the lights show that your Phantom's ready for flight and your telemetry tells you that you've locked onto at least six satellites, start your engines and take her up to two or three feet. This should be high enough to avoid the turbulence caused by your own prop wash, but low enough to preclude any serious crash damage.
5) Test all of your controls to be sure that everything is working precisely as designed.
6) Pay attention to the way the Phantom hovers. Is it pretty much locked down to one co-ordinate or is it hunting around a bit. If there's a bit of wind, it should only drift a bit in the wind's direction and then correct itself. If it's hunting in more than one direction, you really need to do the compass dance*... Some people do the compass dance before EVERY flight, which is probably a very safe way to operate.
7) If all looks to be in order, get that bird up in the sky and fly your *** off !!!
* Compass Dance = Flick the right switch up and down ten times rather quickly. The lights in the back of the Phantom should turn solid yellow. Holding the Phantom upright, turn it 360 degrees, slowly, while keeping it as parallel to the ground as you can. The lights should then go solid green. Now turn the phantom so that either the camera, or the battery, are facing up and turn it 360 degrees. If the compass is happy, you'll get flashing green lights. If not... they'll flash red/yellow. If they're not flashing green... do it again... and again... and again... until they are. Once your compass is working properly, re-test the hover and controls at low height, all over again, until you're convinced all is well...
-slinger