Attached Link: http://www.planit3d.com/source/software_files/3dmod.htm

Modeling clothing is not for beginners, I'm afraid. You cannot do it with Poser. You need a 3D modeling app. Probably most people who model clothing use high-end apps like 3dsMax or Lightwave, that cost big bucks. But there are some free ones available. (See link.)

Shade is another possibility. It's another Curious Labs product, and is available at a special price for Poser owners.

Whatever software you choose, be aware that the learning curve will be steep. You will not learn to make armor in a day. There's a reason why most of us buy clothing others have made, rather than make our own.