Most reefers will tell you to do long extended drip acclimations - "the longer the better"
The issue I have with long drip acclimation is ammonia. In the bag, there is a higher ammonia content than in your tank. At low ph's the ammonia is in the form of ammonium and this is actually fairly non-toxic. The problem is that as you add water from your tank the ph may rise and the ammonium is converted back to ammonia, which is highly toxic. I believe that extended drip acclimations are detrminental as the coral is now exposed to the higher ammonia levels for an extended period.
I think the need for acclimation therefore is somewhat exagerated. I tend to float the bad for 15 minutes add a ~1/2 cup of water every 5 minutes, or so, for ~20 minutes and then throw the coral in. Inverts can be sensitive to salinity changes, so some drip acclimation is ok, but I disagree with many as to how long.
As to light, it depends where it's comming from. If it was at an LFS with similar lighting acclimation probably isn't neccessary. Otherwise, I like to put it in a shady part of the tank for the first day and move it up a little every day, to the desired location. However, corals can bleach from too little light as well as too much, so don't over do it. Again, it really helps to know what the lighting was like where you bought it from. If the ligting was much lower, then longer acclimation is neccessary, if it was higher or the same, then none is neccessary....
Good luck!
