We have some simple videos on audio production with your phone that may be helpful (though there are also loads of these on YouTube too).

In this video, Bok Learning Lab Studio Coordinator Casey Cann explains how to record high quality audio using the iPhone's Voice memo app:

Podcasting using the Voice memo app

And, just in case things DON'T go perfectly in the field, here are a couple of quick tutorials on fixing audio problems in Premiere:

Fixing distant and muffled audio

Fixing loud and distorted audio

Takings Hums out of audio in Premiere