Is 500mb enough data a month for me?

I'm buying an iphone tomorrow and the deal I was looking at offered me 500mb of data. I'd be using it whenever i'm out my house for heavy twitter use, regular tumblr use, next to never facebook use, snapchat and probably often use of uploading to instagram and obviously imessage. Would 500mb be enough? I don't really understand how much gets used up doing what so please help!

Added (1). Also, does my data get used when I use imessage? Not sending pictures on it, just messages? And one last thing, if i exit an app will it still use my data up until I go to Wi-Fi settings and completely turn it off?

Why won't my iphone 4 upload my videos?

It loads all the way to the end then it says "Could not publish "Such and Such Title"" And my internet it working. I'm not logged on to my youtube account on any other devices so what's the problem? It's like a 1 min 31 sec video. There's much longer videos on youtube so it can't be the length of the video…

I can't get my itunes to go into my iphone?

Hi, i just got an iphone yesterday and i want to get all my itunes onto my iphone, all of my itunes are on my ipod though, i tryed logging into itunes on my iphone but none of the songs are on my iphone.

Will iOS 7 be available on the iPhone 3GS?

I have an iPhone 3GS (I know it's sad), and I know iOS 7 is set to be released sometime next week so I was thinking since iOS 6 was released on the 3GS, do you think iOS 7 will be available also?

Good, mid-line iPhone 5 case?

I'm looking into iPhone 5 cases and wondering what a good, middle of the line case would be?
I want something minimal but I do want something that will save it from drops and bending.