Does anyone have any pointers to resources, guidance, etc. on audit in BizTalk?

I'm very new to BizTalk, so maybe I'm missing something entirely

We're looking at our first BizTalk application, fairly simple, file transfer between applications with a bit of transform. However we want to have an audit trail for the various actions, so if needed, we can come back in say a months time and check where the "problem" occurred


Cheers,
SteveC.