I'm new to GMing and RPGs in general, but I'm willing to start a complete campaign after a few sessions with the intro adventures. I'm thinking of using The Enemy Within as a story guide and replace/convert NPC to 3e.
The thing that's really unclear for me is how do I prepare for the story driven part. Do I read the whole book for the campaign and take extensive notes - I'm sure I will forget a lot if I get to read it all at once, even with notes I'm afraid it would still be overwhelming - and even then would the notes be enough? Do I break it into chunks of a session size and read each one thoroughly a couple of times? Is it right if during the session I get to reread parts of the adventure text for myself?