First post, and already some pretty major things to pop up and note. Feel free to add your $0.02/£0.02 (depending on your location), but this is what I've come up with based on a few years of trial, error and some logic. Most of this I guess you could use as a mid-topic 'sum up' for those people who want the questions answering. And before I see any more of the 'where does I shot resin from' posts, for God's sake use Google or go to a local hardware store.
Beware all ye of a non-wall-of-text predisposition. Here be long spiel.
First thing is the creation of your 'base'. This is what you're gonna be stuck with for the rest of the project, so damnit, MAKE SURE IT'S PERFECT. Nothing is worse than getting halfway through glassing your project and realising there's something you needed to do a while back. Perfect base = happy days.
Second: damnit, you freaks. SAFETY FIRST. Get a good respirator AND goggles, or I $#!T ye not, you WILL incur damage at some stage. And it's far better to be safe and a little out of pocket than to do it regardless and have messed-up lungs/eyes/skin. Read the labels on your materials and even if it seems stupid, follow the instructions. A little care and time saves a hell of a lot of pain and embarrassment.
Third: for all you MJOLNIR helm makers specifically. This might seem really dumb, and I'm probably going to get at least ten 'NOOB!' posts for it, but make sure the helmet FITS? Too many times have I seen people make a helmet, then try and put it on only to find it's too small. In some cases they tried to force it and broke it, wasting heck knows how many hours of labor. This goes for the other parts of your armor too, MJOLNIR or otherwise.
Fourth: Fiberglass = interior, resin = exterior. For those of you at home not following, this means the following: don't fiberglass the outside of your piece. This means you'll get a better finish - resin sands a lot better than fiberglass, and since the fiberglass is purely for strength, it's useless applying, sanding, re-applying, re-sanding, painting to something you don't need to apply and paint in the first place. The woof has spoken.
Fifth: please, please, PLEASE do your research before you start. Don't use a resin that's gonna eat through your glue holding the entire shabang together. Ask the people at the desk when you purchase the resin, and if needed, go home and look up the resin before buying to see what it eats through. Glue gun = very yes, if you're careful with where you apply it (too much and you'll end up with huge lumps in your surface that are a pain in the rear to get out and fill).
Finally: resin can be smelly even after it cures. It's one of those things. As has been suggested, use baby powder to dry it out before you sand and paint. Deodorising sprays work, depending on the brand, but your best bet might be to do both.
Next, two things:
First, padding. Anyone have any ideas how you'd do this to make the helm and pieces comfortable and firmly secured?
Second: What's the take on doing this with Elite armors? I need to make two sets, and there's no pep for it.
*prepares for a slew of 'well, I guess you're f***ed then' posts*