hi Greg,
that's a massive task you've got in front of you.
You've got some good basis to build upon: by coming from the everyday Quality area, you have a really good idea what's going on in your production and probably have a good relationship with the production team (which is a huge asset, belive you me).
There's one thing I'd suggest to do asap: get trained. It takes 4 days and it will be a piece of cake because you already know the things they're talking about. It will give you a good insight into the auditing process and into the mindset of an Auditor.
AS9100 is a very strict standard, it's far more complex than TS16949 so I'd start with TS (or better get AS depending on how much your company has budgeted).
Next thing, look at your processes.
Identify the main areas (for example: incoming goods, production - this can be split into areas like stamping, plating, welding..., design & development, purchasing, resources - that's your HR & IT, Quality, test, logistics / shipping...). Then read through the AS standard very carefully and identify which parts of the standard belong to which area (some clauses will apply to more than 1 area).
Next, draw the internal audit plan.
Have you got any other Auditors on site? Make use of them.
If it's just you, then spread the audits so that you're not rushing yourself all the time.
Anything else, please shout. I'm happy to help.