tank size,equitment,if they should go with Fo FOWLR or a reef tank, lighting, substrate and fish of course exc.
-Tank Size: A good size to start off with is a 40gal or a 55gal. some may take it lower but it is easier to keep stable with more volume.
-Equipment: Powerhead (20x turnover), L.R, Substrate(Not needed if your going with BB), Heater,Filter (some people use L.R as there main filter but its always good to have a helping hand), R/O water, Protein Skimmer (Not needed for smaller tanks such as 10gallon tanks), SW master test kit.
-For begginers it would be easier to start of with FOWLR and of course once your tank matures you can promote your tank to a higher degree of difficulty by starting a reef tank.
-Substrate: Sand is preferable but you can also go with BB, some marine fish do need a DSB in order to thrive in a tank so it would be better to get sand (Live sand or Aragonite Sand *spelling?*)
-Fish: A few people who choose to do cycling with fish end up using Damsels since there cheap and hardy. But I always urge people to do Fishless cycling with L.R. Some good ideas for begginers are Gobies,Wrasses (6-line), and of course the good ole' Nemo (Clownfish).
-Lighting: MH is highly reccomended if your going to start a reef tank but if your only going to keep FOWLR then a small 20watt light is acceptable. MH are also very expensive and will drain your budget quickly. There is an alternative but it isnt as good as MH. PC lighting is a good choice to start off with. It really depends on what type of corals your going to keep. Softies,LPS,SPS. Usually most softies do well under PC'S