I would like to say that I still consider myself a beginner. I have so much left to learn. That said, the best advice that I could give to anyone interested in the hobby is "Just do it!" (*I am in no way affiliated with Nike, and this is not a subtle attempt at promotion.
*) I think that encouragement is the area people entrenched in this hobby lack the most in. I would also tell them that keeping a reef isn't for everyone. It takes an attention-oriented, animal loving personality who is willing to spend upwards of a thousand dollars just to have a small slice of the ocean in their home. It is a never ending commitment, and some of these animals may very well out-live you. It is a series responsibility, but one that is not out of your reach. It is the most rewarding hobby I have ever been involved with. Then I would them three more things. First, read, read, and then read some more. Second "Nothing good happens in a reef fast." Third, Look at my signature.
-ignatz
"It takes a villiage to raise a reef."

-ignatz
"It takes a villiage to raise a reef."