Will I be able to use iPhone? OLD VERSION!?

Okay, so i'm getting an iPhone (not 3g!) off craigslist tmr. It's used.. but brand new condition. So let's get that on the side. My question is will I be able to use it? I will unlock it, so it can be used with any service provider. But will I be charged for going on the internet or stuff like that? Will I get any charge at all for using the iPhone? My phone plan is basic, only calling back and forth, no voice mail or txting, or caller ID.. or data. All I have to do is turn off EDGE to avoid charges right?
Uhm.. rich I already know that?
You guys are TOTALLY... off what i'm saying wtf. It's totally off topic from what i'm saying.. all i'm asking is.. I won't get charged if EDGE is turned off right? Just using wi-fi. wtf where is all this jiberish coming from?
Uhh Raulh.. D? Where on earth did I ask if I can use it anywhere? if you can't read don't answer. I know what your trying to do.. get points.
Okay.. way2perfect.. and other people asking what service provider i'm using. Can you honestly shut up and stop asking? I'm canadian and using Fido. Why ON EARTH? Does it matter? ALL im asking is.. Will I get charged for using wi-fi or using iPhone in general when my EDGE is turned off? It's that simple. Yes and No. with back up holy crap?