Yep if you have dark skin then dark hair goes well, light skin then lighter hair colours. But I think very pale skin and black hair looks good, but not blonde hair and dark skin.
A lot of italian and spanish people have tan skin and dark hair and it looks LUSH. But be careful with "black". There are lots of various shades of black (!) and if you go totally blue-black, it will just looked dyed. You shouldn't go more than 3 shades one way or the other- your hairdresser will be able to help you with it!
I've had my hair black for a few months. I am quite pale-skinned so I just slap on the fake tan lol. It is cool having black hair as not that many people have it. Unfortunately, you do have to put up with being called Kat Slater which is sooo annoying. I just remind them that there are other ppl with black hair i.e The Corrs, Kym Marsh etc. Go for it!