Get a book called The New Aquarium by Micheal Paletta, good book for beginners,
Here's a list anyway:
If you want a Reef Tank, then you'll need to invest in better lighting.
Thermometer
Heater
Filter- Canister or Wet/Dry w/return Pump/check valve
Protein Skimmer
Power Head
Timer
Salt
Live Sand or Crushed Coral
Live Rock
Water Test Kits
Refractometer or a Hydrometer(unaccurate)
Fish Net
MagFloat
Bucket
Quarentine Tank if possible.
Water
Fish
Good Luck, any other questions ask on this site, the people here have helped me alot and are very informative, I'm still asking questions,