Save your SHSH to your computer and Cydia so you can always downgrade.
Works on iPod iPad and iPhone all versions.
Website for Umbrella:
http://thefirmwareumbrella.blogspot.com/
Windows:
Step 1. Before starting download this small utility usbview Download Here:
http://www.ftdichip.com/Resources/Utilities/usbview.zip
Step 2. Open usbview you downloaded earlier.
Step 3. In "options", check off "config descriptors" (enable)
Step 4. Hit F5 on your keyboard to refresh
Step 5. Scroll down till you see "Apple Recovery (iBoot) USB drive, and click on it.
Step 6. Copy the ECID number and past it into Umbrella.
