You will find many iPhone jailbreaking guides on the web. But most of them are unreliable and might present troublesome problems for new iPhone owners.
If you are not familiar with Cydia, it is the store for apps not authorized by Apple. Basically, Cydia is what you jailbreak your phone for. Recognizing that there were many iPhone owners unable to find reliable jailbreaking guides and unable to take advantage of Cydia, Cydia’s owner (Jay Freeman) decided to take matters into his own hands.
Freeman recorded the video regarding the iPhone 4 jailbreak being developed by @comex, @musclenerd, and @planetbeing. His mention of this jailbreak makes it reliable. Check out the video to find what Freeman had to say about the jailbreaking process.