NOTE: Those of you who rely on a carrier unlock MUST STAY AWAY from Redsn0w and stock iOS 4.3.2 firmware. Also, the patches for 4.3.2 are said to be broken on this version of Redsn0w. PwnageTool 4.3 with 4.3.2 PwnageTool bundles is the recommended.
How to jailbreak iOS 4.3.2 using Redsn0w on Windows and Mac:
Download iOS 4.3.1 (required by Redsn0w 0.9.6 for 4.3.2 jailbreak) for your version of iOS device.
Update/Restore to iOS 4.3.2 firmware using the IPSW file you just downloaded via iTunes 10.2.1.
Start Redsn0w and point it to the official iOS 4.3.1 firmware file (NOT iOS 4.3.2 file).
Create a folder on your desktop called Pwnage
Download RedSn0w from here and place it in the Pwnage folder. Likewise, download the latest 4.3.1 firmware from below and place it in the same folder.
4.3.1 (4 GSM):Download iPhone3,1_4.3.1_8G4_Restore.ipsw
Once iTunes has finished updating your iPhone to the desired firmware open the Pwnage folder on your desktop and launch the redsn0w application from the redsn0w folder we extracted earlier.
Make sure Cydia is selected and click the Next button to continue
RedSn0w will now guide you through the steps to get into DFU mode. You can find more help with DFU mode here
Once this is complete you will be notified that RedSn0w is done. Click the Finish button. When your iPhone finishes rebooting (5 minutes or so) it will be jailbroken with Cydia on the SpringBoard.
REMEMBER THAT AFTER YOU DONE JAILBREAKING IT YOUR IDIVICE WILL NOT BOOT IT WILL STAY ON THE APPLE LOGO, SO HERE IS WAHT YOU DO, FOLLOW ALL THE STEPS AGAIN BUT ON STEP 8 DO NOT SELECT CYDIA AGAIN JUST SELECT JUSTBOOT TETHERED RIGHT NOW. AND THAT’S IT BUT EVERY TIME YOU TURN YOUR PHONE OR IPOD OFF YOU WILL HAVE TO DO THAT, TILL A UNTETHERED JAILBREAK IS OUT.