hello,,, sorry i am new to jb and unlock

currently i m having lock iphone 3g with 2.28 baseband and still on version 2.2 running on yellowsn0w
i had read through tutorial on upgrading to iphone os 3.0 but got confusion on the version of itunes to use,, according to devteam that the itunes 8.2 can lock the pwn and jailbreak and there's also people use the latest itunes to upgrade to OS 3.0.
so which version of itunes to use if i want to restore to iphone OS 3.0?
Thks.