Saving images to webserver

[John Allijn]

Hi
I'm working on a mobile app for iOS. In this app I would like to enable the user to take a picture and then save it to my webserver at a hosting provider (shared hosting). 

I'v been looking at different ways to do that but can't figure out where to start. 

What is the best way to save pictures and how do I handle the image data? 
Should I create a php or html file? If so, what methods can I use to save the file to a directory? (I can handle the ios part i think. My only blind spot here is the server side)