The latest updates are actually pretty minor, but if you have an iPhone 3GS or iPhone 4 you might want to check them out because they fix an issue with the vibration switch. If you’ve already jailbroken your phone, you can just run redsn0w 0.9.6rc16. It should work even if you have a custom IPSW. If you haven’t jailbroken yet, you can grab the tool that best meets your needs and go from there.
Redsn0w is a pretty basic tool for jailbreaking your iOS device to run apps that aren’t available from the iTunes App Store. PwnageTool lets Mac users create custom firmware with custom boot logos while performing advanced hacks such as preserving you baseband and installing a carrier unlocking utility. Sn0wbreeze is a custom firmware creator for Windows.
If you’re using redsn0w, you can follow my step by step instructions for jailbreaking an iPhone, iPod touch, or iPad.