Well, let me see, there are five basic ways to harden and finish armour.
-Resin and Fiberglass
-Hot Glue Method
-Smooth-cast Method
-Rondo Glassing Method(Pour Resin mixed with Bondo to make Rondo into your armour piece. Then add fiberglass to reinforce it)
I have personally used all four ways, and I have to say that Rondo glassing is by FAR, the easiest, fastest, and awesomest way to make armour.
for the tutorials, just look at the stickies (for the first three I pointed out). For the Rondo Glassing tutorual, use the search function, or look in the Pepakura and Cardboard Armour Section of the forum.
If you need any further help, from scaling and printing the armour to finishing it, feel free to PM me any time. I will do my best to answer, and I always have some space in my inbox available.
Good luck, and hope to see some progress soon.
Cheers!