How do I jailbreak my Iphone 3Gs? Which program?

I have a new IPhone 3GS firmware 3.1.3.

Where do I start on jailbreaking my iphone? All I have read is about older versions, new bootroms, etc.

How to jailbreak iPhone with blackra1n after Apple Update?

Okay my iPhone was jailbroken for awhile. I had apps from Cydia and my iPhone all customized to my liking. Last night I got an update from iTunes to update my iPhone. After the update I checked my iPhone and everything I got from Cydia was GONE. I attempted to jailbreak again with blackra1n and its not letting me. Please help!!!

Is there way to jailbreak the iPhone 3Gs with 3.1.3 firmware?

I want to jailbreak my iPhone but I couldn't find a way to do it with the firmware 3.1.3. If there is a way please tell me. If it works I will vote best answer!