Overall, I think feeding, if done right with the right foods, can offer something extra for the corals. But I think that the wrong foods, done wrong, can cause a lot more problems than most newer hobbyists are prepared to deal with. I know for a fact that not feeding is fine, my tank is proof. Could it be slightly better if I fed? Sure, maybe..or not. But it is doing exceptionally well without, so I'll stick with that
So until one is experienced enough to start dumping things in the tank that may need to be removed, I always advise to err on the side of caution.
If you really want to feed, the best I've read about is rotifers, although running a culture for those could be a hobby in itself.