Help me please ASAP

Hello everyone !. tomorrow said to say it but i'm getting a blackberry 8900 Curve. I need it for work and this battery life in horrible. Tomorrow i am meeting up and trading it and he's also giving me $50 . Question is , how do i get my contacts off my iphone. what is some good security things i should do so that he cant like you no get my info. what should i do. i took my sim card out and my contacts are still there. Are all my contacts on my sim card already ? please, quick answers im getting it tomorrow morning haha.