I feel like I should throw my 2-cents in, since it's my idea.
The first issue should be introductory, something you could hand someone to read that explains the game, without ruining it.
Cover: The Coredump symbol, obviously ... Title above (just 'Coredump'?) ... then some of the usual article titles. I was picturing it as black and white, maybe even constructed on a photocopier where you can tell they cut out each piece and taped it down? That might come off as too forced, though.
Articles:
1) What is Coredump: Storyline only, no mention of it being an ARG, no spoilers. I was thinking of including the image from this week's puzzle-test, and basically suggesting the author and his friends solved it, and discovered the first Coredump system. Then, researched it, and the article is the result of that research.
2) Your first run: A walkthrough of the first node, with detailed explinations of downloading a few different mud clients, exactly what to do to get set up, stuff like that.
3) Getting Old School: Because the Coredump was big in the 90's, a lot of the software downloaded will depend on things like DOS, UUENCODE, and PKZIP. Things a 90's kid will remember fondly, but most people under 30 will find baffling. So, walk the player through installing DOSBOX, suggest some downloads, give good examples.
4) Comic: I used to draw (terrible) comics. I miss it. I was planning to do a comic or two as filler.
5) Cut-out/Stencils: If you ever read Channel Zero, you know what I'm thinking. If not, go read Brian Wood's Channel Zero. Seriously, right now. This can wait.
I was also thinking of tossing in something about 'real' hacking ... something I could work into a puzzle later. The same with hardware ... I like the idea of seeding puzzles by basically giving them the instuctions first, then having them run into the puzzle later. Also, a collection of 'zines could be useful down the road.
The same goes for making some kind of wearable stuff ... maybe go over a really basic wearable pi build from the ground up, explaining it as a 'burner' system, that you don't have to worry about ditching in a hurry, and it's not 'the family computer' or a 'work laptop', so you don't have to worry about it getting fried by a virus from the game.
So, when this was just something I was putting together for my friends, that's what I was going to. If no one jumps in, that's pretty much what it'll be.
EDIT
I was thinking 8.5x11 inch white paper, folded and stapled in the middle. Nothing fancy, could be printed at home.