Wow, quite a lot of things.....
Feel free to instant message me : Rhyfelmarch
I have a 24ap and I love it.
I suppose I would first recommend doing some reading, if you already have, great. I would get a heater for the tank, as well as either buy saltwater or start mixing it.
You will need a general test kit, and I recommend a refractometer for testing salinity if you mix your own salt.
Then you can move on to live rock and live sand....