redsn0w 0.9.6 RC 12 has just been released by the Dev Team and the only novelty it brings is solving the problems with the animated boot logos that some users still had. Nothing new has been introduced and you can run this new version over the old one without any problems.
You can download redsn0w 0.9.6 RC12 from here: Windows, Mac OS X . You have jailbreak tutorials here.