by far the best app for doing this kind of organization is evernote, especially if you become a premium member. i think ios is probably one of their weakest apps (compared to mac, android, and windows), but it is still an app i use all day every day.
I also recommend Evernote, even if the iOS app is a bit weak. The selling point for me is that it's cross-platform, so I have Evernote on my iPad, my BlackBerry & my PC laptop. I can access my Evernote account on the Web as well (so on any computer) since it's cloud-based.