If you already know it all about unlocking and are just looking for guides and tutorials, then scroll down to find instructions on how to Unlock.
Simply look for the firmware version you want to unlock and the type of iPhone you have, then click on the link to see a detailed tutorial.
iPhone 4S Unlocking Guides
iPhone 4 Unlocking Guides
iPhone 3GS Unlocking Guides
iPhone 3G Unlocking Guides