...and any help would be greatly appreciated. I should warn that I'm pretty new to all of this!

I jailbroke my iPhone previously using QuickPwn and had no problems doing so, infact it worked like a treat. With 3.0's release, I've obviously been looking at doing the same again. I was going to wait until QuickPwn came out (although I now know redsn0w is the new QuickPwn) but saw that PwnageTool did the jailbreaking part (I've no need to unlock my iPhone) so I tried doing so that way. And while I succeeded, I found that doing so overwrote everything on the phone and essentially made it new again. Which isn't really what I wanted to do; I just wanted to jailbreak what I already had, as I'd previously done.

So I'm now looking at doing so with redsn0w, but looking at the tutorial on iClarified it seems to involve downloading the firmware. The thing is, I've already upgraded to 3.0 (I assumed - perhaps wrongly - that I'd simply be able to jailbreak that in the same manner I had last time). So my question is: will using redsn0w overwrite everything I have, or will it merely jailbreak it but leave things such as contacts, apps etc? If not, is there any way in which I can essentially save contacts, pictures, texts etc, use redsn0w, then reimport them after I've jailbroken the phone?