[Osuka]

So the iPhone I have is jailbroken and unlocked since
its not activated and I wanna put music in it and was wondering if
it would delete the jailbreak files or whatever when connecting
to a new iTunes and erase to sync? Since I'm scared I wont be
able to use it anymore since it might ask for sim card. :(

[Maravilla]

A sync will not remove the jailbreak or lock it up. Just don't restore or update in iTunes.

[Grin]

It will remove music, applications, or preexisting content. The jailbreak however, will not be modified.

[villium]

Yeah what the others say, it's completely safe to use iTunes while on a Jailbreaked device :)