Go to
http://www.dharmatrading.com/ They have a ton of info, and good prices on anything to do with fiber and dying.
I have dyed corduroy. The finished result will all depend on the fiber content, cotton takes dye very well, but man made fibers can be tricky.
A fiber reactive dye is easy to use, it is a few steps, but I have gotten very good blacks on napped fabric, which corduroy is, as is velvet and a few other type of fabric.
You will need to wash the item you want to dye, and DO NOT dry it. If you have used fabric softners, sheets or liquid or any other form, the fabric of the item you want to dye will have deposits of the softner sitting on the fabric, one of the reasons you need to wash it. The other reason is that wet fabric dyes more evenly then dry.
In the past I have used several different colors of black on the same piece of fabric/cloth to get the color I wanted. Some black dyes are based on red, some on blue, and I even had one based on green... I dyed, washed, and dryed the piece after each dye job so the dye would be fast, that is not bleed.
I usuall dye in my front load washer, it has a stainless steel drum, and have used a porcelin lined top loader. It takes a lot more dye, and more rincing/washing. Even if you think you have all the extra dye washed out, wash it again. And if you really want to be sure use a Dye Grab sheet, which I get in the grocery store...
Really this is so much easier then you think. Dharma has all the info on line, and will help you with more if you call them. Remember that stains will dye different then the rest of the piece, and color is different depending on the heat of the water, the hardness of the water, and the length of time you have the item in the dye bath.
Hope this helped....best of luck!