For this you will need : redsn0w Windows / Mac
IPSW 4.2.1 or 4.1 for your iphone Get Them Here
Ipad 3.2.2 ipsw Here Also

If you need unlock, you can get ipad baseband from the link's above.

Redsn0w 4.1 & 4.2.1 Jailbreak Tutorial ;


1) Download iOS 4.2.1 for your version of iOS device. (or ios 4.1 depending which shsh's you have saved)

2) Update/Restore to iOS 4.2.1 firmware using the IPSW file you just downloaded (press SHIFT + Restore button on windows or option + restore on a Mac)

3) Start Redsn0w 0.9.6b4 and point it to iOS 4.2.1 or 4.1 firmware and wait for the ipsw to be ok'd to proceed.

4) Now select “Install Cydia� and click “Next� . Optionally (if you need UNLOCK, then select 'ipad baseband' also)

5) Make sure your phone is turned OFF and it is PLUGGED IN. Click Next

6) Proceed with the step's on screen, to put the phone into DFU Mode.

7) Once this as been done successfully, the phone will start jailbreaking. The whole process may take 5 minute's. Then it will reboot automatically, and the phone should now be jailbroken.

NOTE!!

If you have an iphone 4 / 3g[s] new bootrom / ipod touch 4g, 3g, 2g or an ipad, this will be a tethered jailbreak.
SO from here onwards, whenever you want to do anything related to jailbreak like SSH'ing into your device, or running Cydia, you must first run your device in the so called “jailbroken state� on every reboot by using “Just boot tethered right now� option in Redsn0w.

Although the newest redsn0w may not apply to the above.


ERROR'S


If you have a blank cydia that won't open - Re-run redsn0w, selecting only the install cydia option.

If the phone goes into recovery mode for some reason - hook up to redsn0w and select only the 'Boot tethered right now' option. If that fail's Use Tiny Umbrella and press the 'kick out of recovery mode' Button.

If the phone is in a reboot loop (consant apple logo) - Try re-installing redsn0w, selecting only the