How do I upload a file using Objective C for iOS? I\'m really stuck. I can upload an image using UIImagePickerController, but is there such a thing for .pdf/.doc files?
No, there isn't, assuming you mean pdfs belonging to iBooks and docs belongs to Pages.
There is no centralised storage on iOS for such documents, and your application cannot access files that belong to other applications.
If the pdf & .docs are stored within your application, you can write your own picker. It might be worth explaining your use case a bit more, as there may be a way to achieve what you want.
You can integrate one of the open-source http server like this one to your app.