Leds

[The Guy]

I'm wondering if I'm the only reefer out there that really has limited knowledge on using leds as to what colors are best at what intensity, you hear comments like blues, super blues, royal blues, purples, greens and reds and on and on it goes are best for this that and the other corals.
Par ratings are a real mystery for me, along with most depth related suggested settings. I've been just setting the intensity to what looks good in the tank and most corals are doing ok, having said all this does anyone out there have any idea on proper led use.
I know a lot depends on what you keep sps, lps, softies etc. dictate colors and settings and that's about the extent of what I know.
Anyone know of a good site to read, is there anything like "Leds for Dummies" out there.