IOS7 won't install on iPhone 5?

I've downloaded iOS7 but it won't install. Is anyone else having the same problem? If you have it installed already or know how to do it, or have information about it I would appreciate some help please. Also is there anything to be concerned about on the new update? I heard it was kinda buggy. Please help! Thank you.

Added (1). It is installing right now. I guess there's just so many people installing it there's a lot of traffic, I've tried and waited for about 4 hours, 2 hours downloading 2 hours trying to install. I hope everyone else has better luck! I suppose you have to keep trying till it works.

If you are not connected to Wi-Fi then it will not install. Make sure to connect to Wi-Fi. Hope I helped

Hi you need to be connected to Wi-Fi rather than cellular 3G or 4g
Be prepared to wait a long time as everyone's downloading it so its taking long