First thing I'd say is take everything slowly. Make sure you properly cycle the tank without any living creatures inside the tank. Research everything you put in your tank a lot so you don't end up with things being eaten or dieing. Never listen to your Lfs
without doing your research. I'd advise to look at the specific fish you want before buying anything too for example a blot of people start ith clowns which is all well and good except if you decide you want triggers or lion fish it's not oing to end well.
Equipment wise you'll need around 1lb live rock per gallon, power heads that will turn your tank over about 10 times per hour, skimmer dependant on tank size, sump would be advisable.
What set up do you have in mind?