There's some basic information here:

http://voices.yahoo.com/understanding-textures-materials-3d-6448982.html

You can create material zones in your modeling software or in an application like UVMapper: http://www.uvmapper.com/

Ducky here has three material zones (represented by different colors), allowing you to use different colors or image maps for the beak, eyes and body. You can open the template (created in UVMapper) in any image editing program and paint the zones as you wish. You can also assign simple colors to each one in Poser or create procedural textures for them.

Transmap is short for transparency map. It enables you to make part of an object fully or partially transparent. The maps are simply image files using colors from black to white where white is completely opaque and black is completely transparent (IIRC) shades of gray range in between in transparency. They're often used for clothing e.g. a dress with tears in it or a scalloped hem. If Ducky were in a shooting gallery, you could put holes in him by using a completely white transparency map with black circles where you wanted the holes to be. Hopefully that is correct. You should be able to find all of the information you need inb the Poser manual or various web tutorials.

"Democracy is a pathetic belief in the collective wisdom of individual ignorance." - H. L. Mencken