If there is, could you give me a complete guide?
I havent been able to get a straight answer on whether or not I am able to jailbreak with this os and baseband.

I've looked into the newer redsn0w program which claims to be able to grant an untethered jailbreak to 3gs 4.2.1, but I was not sure about the baseband being able to work with this. And I know at the moment redsn0w 0.9.7b6 is only available for mac. So if anyone using the mac program has been successful with this, let me know.