The mythical, yes they are mythical, iPhone Dev team has released an updated version of redsn0w 0.9.10b5, which includes the fix for the iBooks issue involving DRM.

We remind you that this version of redsn0w is capable of untethered jailbreak iPhone 4, iPhone 3GS, iPad (first generation) and iPod touch (third and fourth generation), running on iOS 5.0.1.

Even If your jailbroken device is not affected by the iBooks bug, it is recommended to apply this jailbreak on top of the existing one making sure you un-select install Cydia in the options.
Alternatively, which is also quicker and easier, you can install the Corona package from Cydia. It is the same file, therefore doesn’t really matter which one you choose.

If you need a tutorial to jailbreak using redsn0w, here we have one.

Download
Download

iPhone 4S users and iPad 2 users should use Absinthe to jailbreak their devices.