First of all, read all the stickies and the tutorials. This will teach you everything that you need to know. The rest is just hands on for experience. Read this all the way through and it will answer any questions you may have. Thanks to Frizzlefry: Tutorial: How to use Pepakura to make your Mjolnir Armor
You'll have to download Designer then. Once you scale it and get all the pieces in place, you need to either print it or pdf it. Or you can buy the program and save changes.