If you go to askdavetaylor.com he has something on jail breaking your iphone.
He is really good at helping people that aren't exactly electronically smart.
Hopefully this link works for you.
www.askdavetaylor.com/how_to_unlock_jailbreak_apple_iphone_3g.html
If not go to askdavetaylor.com look to your right for the search bar and type "iphone" and scroll down till you see something about unlocking/jailbreaking.
