How do I figure out what coral needs what kind of light?

Unforunately there is nothing difinitive. Even gives people a subject to argue about.

The closest I have found is "Aquarium Corals" by Eric Borneman.

If you have something specific in mind let me know & I wil let you know what is says about it.

 

Generally, SPS, clams etc. need very bright light if you want good colors. Mushrooms probably require the least amount of light.
I think LPS is somewhat in the middle. Some coral will look more colorful with brighter light and good water quality.
I'd say you probably want Metal Halides or some bright T5 bulbs for SPS and LPS. Mushrooms and most soft corals can usually make do with VHOs.
I'd recommend buying a book on coral and keep reading and asking questions on the forum. I have an invertebrates book by shimek and a coral propagation book by calfo that have some good information, though I don't recall how indepth they go into lighting requirements.
Chris
edit: That book by Borneman is good. I forgot I had that one too.

 

Each coral species has it's own unique requirements. Each is it's own animal and though some general statements are true(such as SPS require a lot of light) ,  you'll find some SPS live in deeper water with stronger currents and some live in 6 foot of water with slower currents but they are both SPS.
I think generally, SPS require metal halides/T5s and and 20x turnover rate an hour. ( I think)
I learned everything from reading the reefcentral forums, from club members and from talking to people like Anthony Calfo, Mitch(from Omaha Zoo) and Mike Paletta when they have spoken at our club meetings.

Like was previously said, check out that borneman book called Aquarium Corals. Eric Borneman is pretty much THE coral guy for aquariums.

 

Borneman actually has his own forum over on Marine Depot. He is easy to talk to & will give you an honest opinion. He helped me alot on planning my new tanks.

 

I dont know of any sources, but I will share my experience.

You can keep all kinds of corals (sps,lps,softies) under flourecent lights (VHO, PC, T5), but it won't be easy to keep the sps colorful and growing well (except under t5s). Generally soft corals do best under this kind of lighting, even better than under metal halides most of the time. Otherwise halides are pretty much the most diverse, you can keep anything under them if you place the corals in the right positions. Just be careful not to burn the corals by placing them directly under them. It is always best to start everything low in the tank and move them up based on their reaction to the amount of light they are receiving. I can tell you that you won't have much luck keeping mushrooms unless they are at the very bottom. SPS colors will generally be more vibrant the higher you move them up, but that is not always the case and you need to slowly acclimate them to the intense light. I wish I could give you more of an exact answer, but you will figure it out as you go along. Start with some cheaper/easier corals like mushrooms, zoas, leathers. For sps, Montipora digitata, capricornis, green slimer, and birdsnest are all pretty easy and cheap beginner corals. Look for signs to see if they look happy. If their polyps are retracted they are probably getting too much light, if they are extended more than usually and have a transparent look, then they are probably not getting enough light.