Table 310.13 and 400.4 are helpfull.
Otherwise, spend some time at the big box stores and check out the different selections of wiring methods and materials. This is a good way to attach the name of a product to what it looks like.
When I instructed a first year apprenticeship class, I would make arrangements to meet at a local supply house that allowed me to tour the stock room. The students always remarked how helpful that lesson was.
I also believe the American Electrician's Handbook provides good detail and pictures of all sorts of wiring methods and materials.
