Just for reference, corals usually fall into 3 main categories:
Soft - These corals have no solid skeleton of any kind. They are more or less just flesh. Corals of this type are generally pretty easy to care for. They include Leathers, Polyps (though these are not technically corals but for all intents and purposes...), mushrooms, Xenia, Zoos, etc...
LPS - Large Polyp Stony - These have a skeleton and exist in two main forms. First, as a single solitary polyp, such as brains, tongues, fungia, Elegance, etc. Second, as a colony of smaller (but still comparatively large) polyps, such as Hammer, Frogspawn, Candy Cane, Torch. Generally the multiple polyp varieties are easy enough for newbies to keep. The large single polyp can be more difficult.
SPS - Small Polyp Stony - As described above.
Other things, like feather dusters, anemones, clams, etc are sometimes confused as corals, but they are technically invertebrates of different types. Dusters are worms, anemones are anemones, clams (along with sponges) are bivalves, but none are corals.
Hope this helps.
Consider picking up a book called "The Conciencious Marine Aquarist" by Bob Fenner. It's an awesome book for a beginner. Read it cover to cover (also read the Fair tax book, but that's another topic).