Introduction: Jailbreaking Your IDevice (4.2.1 - Untethered)
NOTE: These are not my photos. Though I have jailbroken mine, I lost my camera...
I'm sorry I have no photos. No cameras available.
Anyway, on with the jailbreak. OK, First, you need to go to settings, then General, then you hit About.
OK. Once you have hit About, scroll down to Version. It should say a number. That's your firmware. Now this tutorial SPECIFICALLY is for firmware 4.2.1, so you may not be supported by this. Though you will at least have an idea of what to do.
This jailbreak is Greenpois0n, so you will download the jailbreak file from this link: http://greenpois0n.com/
OK, once you have downloaded it, extract it (I'm doing this on Windows, not Mac by the way.) and wait for it to finish. Then find the extracted file, and it should have an Apple Skull logo. Click on it and start it up. It will tell you the directions step by step what to do.
Don't get worried if your iDevice has hundreds of lines of white code on the black screen. This is totally fine and everything is working perfectly. Once it has finished, Slide it on and search for Loader. It will load Cydia onto your iDevice. Cydia is like an appstore, except it has themes, like keyboard colors, lock screens, Boot Logos (Mine has an XBOX 360 load up,) and don't forget to get WinterBoard. I don't quite remember how I got it. *Laughs* Anyway, Jailbroken vs Un-Jailbroken, Jailbroken wins. Unless you screw up your iDevice like I did earlier. That's not my fault, well me screwing up my iPod is my fault, but... you get the point. Listen to the directions and everything will be a breeze, though. Have a great time with your jailbreak! Hope to put up photos soon.