Best way to jailbreak an iPhone 4?

I've always wanted to jailbreak my iPhone but I never knew how and I don't want to mess up my phone! So can someone show me the the newest and safest way to jailbreak my iPhone 4?

Does not affect your phone and if it did just restore it

Depends what version your in

you would have to go to settings then general then about and scroll down to version
ones you have version number just go on youtube and put your version and then jailbreak and look at a tutorial

Best and easiest way will be to use evasi0n - Best tutorial and download links below

Evasi0n download links (Direct links) - http://www.evasionjailbreak.org/evasion-jailbreak-download-evasi0n/

iOS 6.1.2 and other iOS download link - http://www.evasionjailbreak.org/ios-firmware-download/

Evasi0n 1.5 jailbreak tutorial (step by step) - http://www.evasionjailbreak.org/evasion-6-1-2-jailbreak-1-4-evasi0n/