Urgent iphone setup/activation query

Hi,i am about to buy a factory unlocked apple iphone4 this New Year and this will be my first iphone.Q1.My question is that can i start using the iphone with my existing micro sim as soon as i open the box without setting it up in itunes?Q2.Before setting up the iphone in itunes do i have to insert the micro sim in the iphone and then connect it to itunes or i can just plug the iphone into itunes without a micro sim card and set it up in itunes?,also while connecting the iphone to the computer should it be in power on or off mode?Please help!I checked out a lot of iphone setup tutorials but none of them mentioned the answer to the above specified queries.Any help would be appreciated.Thanks.

 

Thank you very much for solving my query!!