First CC Advice Please

Hi andovia212 
Well, you can find our tutorial list here
You will need to learn to use blender to mesh the parts yourself. I advise you following some mesh creation tutorials as there are many steps that need to be properly followed.

To make prosthetic limbs, you will basically need to make clothes.
The issue is that you cannot simply replace part of an existing mesh. That means that if you want to create a prosthetic for an arm, you will make it with a top or full body piece of clothing. So this prosthetic will only be "attached" to this piece of clothing. To vary the clothes you will need to clone another piece of clothes, attach your prosthetic arm (do all the relevant changes that need to be done to textures/bump map etc) and finalise your package.
For legs it would be even worst as you would need to edit shoes and bottom/full body as the mesh would be split between shoes and bottom/fullbody. In result you would display the limb properly only when the sim wear the proper shoes+bottom.

I don't mean it is impossible at all, but you would need to make a lot of them to be able to vary the outfits (which is maybe for you a minor problem in the first place, dunno ^^).
Or you make only one and alway wear the same clothes with your prosthetics then :p