Factory Unlocked 3G S - Activation & Set-up T-Mobile USA

I'm about to acquire a new factory unlocked (not hacked/jailbroken) Apple iPhone 3G S 32GB and seeking guidance in the correct steps to both activate the phone and how to set it up on T-Moblie USA for voice calling, voice mail, SMS, MMS and internet access. I will also be needing to configuring the phone POP3/iMAP email as well as synching to my laptop Mac for contacts, calendar, and iTunes music.

Any instructions/pointers are appreciated and can be sent to my private email.

Also any advise about the data plans. I live in the LA metro area.

TIA!