iPhone Dev-Team has released the latest version of the redsn0w jailbreak tool, which will jailbreak the original iPad untethered in a few easy steps. Redsn0w is available for both Mac OS X and Windows computers, and will jailbreak iOS 5.0.1 firmware.
Before you follow the instructions below, make sure your iPad is running the latest stock Apple firmware, version 5.0.1. This can be checked by navigating to Settings -> General -> About -> Version. Updating the iPad over-the-air (OTA) requires iOS 5.0 to be installed first. Otherwise an update to 5.0.1 can be performed using iTunes on your computer.
Follow these instructions to jailbreak untethered and install the Cydia app store on your iPad:
1. Plug your iPad into the computer, then turn it off. The iPad must be off, not sleeping.
2. Download redsn0w to your computer and unzip the archive. Links to the latest redsn0w version can be found for Mac OS X and Windows on the iPhone Dev-Team blog.
3. Run the redsn0w application. Windows users must run redsn0w as an Administrator.
4. Click the Jailbreak button.
5. Redsn0w walks you through the process of putting the iPad into DFU mode. Click Back to start over if you miss a step or the iPad is not detected by redsn0w.
6. Redsn0w will reboot the iPad after detecting the device in DFU mode.
7. When redsn0w says "Please select your options" be sure the Install Cydia box is checked then click Next.
8. The iPad will reboot, and the rest of the jailbreak process will take place on the iPad.
9. The iPad is now jailbroken and Cydia is installed.
The first time you run Cydia (the jailbreak app store) the software initializes, which takes a few minutes. When this is complete, navigate to Changes and tap Refresh in the upper left hand corner. This updates the list of packages available.
Your iOS settings and any apps you had installed before the jailbreak remain on your iPad after the redsn0w process is complete. iPad 2 owners stay tuned, developer pod2g is working on bringing the jailbreak to A5 devices as soon as possible!