First thing's first...
Filtration.
With reef, a top of the line filtration system is a must. Your system should include (but not be limited to):
A Refugium
A Protein Skimmer
A Canister Filter
What media for the canister filter? Not Bioballs. Bioballs need to be rinsed and cleaned well every month or two otherwise they become a Nitrate factory. What I recommend would be Seachem's Purigen, which acts somewhat like a protein skimmer. It absorbs dissolved organic matters before they can decompose. To filter out the Ammonia, Nitrite, and Nitrate, I would choose Seachem's Matrix. It is a super-porous stone material that has enough surface area for Aerobic and Anaerobic bacteria, which will complete the Nitrogen (Nitrate) cycle.
The canister filter I would recommend is either a Hydor, or a Fluval.
Recommended protein skimmers include the Aquamedic Acone, Coralife 75, and the Hydor Slim Skim (if you have a refugium large enough for it).
For reef, strong lighting is needed. Depending on what corals you plan to grow, there is a vast array of options, but in my opinion, LED is the only way to go. LED bulbs last ten years (at about 10 hours a day), and depending on the watt per unit, can grow any coral. I have two 170 Watt units over my 90 gallon reef, and they work wonders. For growing reef, it is recommended to have at least 1 watt per gallon if you are using LED, or 4 watts per gallon if you use t5 HO lighting. If you only want soft corals and maybe some LPS, I would NOT recommend lighting as powerful as mine. You can get far cheaper systems specifically for softies and LPS.
Finally, you need water movement. The water moving is how corals get their food (besides photosynthesis), and some coral need higher movement than others. Once again, SPS needs higher movement than LPS and softies will, so if you don't plan to get SPS, go cheaper on water pumps or wavemakers.
Recommended wavemaker:
Aquamedic EcoDrift 8.0, this wavemaker has different wave settings, pump strengths, and frequencies. Up to 2,000 Gallons Per Hour, it also has a daylight sensor, so at night it turns it's power down for lower water movement like in nature at night.
That's about it... good luck!