Ahh, you will learn so much in "the world of saltwater." I was the same, and the first thing I need to reccomend to you is to research, research and research. It is great you are asking these questions before investing.
I have a 10G Nano-reef that isnt making much progress right now, but I hope to get some corals in it soon.
The fish question is the one that has a ton of answers. Everyone likes different things, and I say this to everyone who asks this: Why dont you go to your LFS, and write down the names of the fish you like? Then, post them here so we can make the best decision for you.
LR should generall be at least 1-2lbs per gallon. Make sure you get the light, pourous rock so more things can live in it, as LR and LS is the main source of filtration in a tank. Sand is different though. Some say you absolutley have to have a 4" sand bed, while others say 2", 3", or even none is fine. I, myself, have a 2.5" bed, and think it is fine. A 4"+ sand bed is perfect for biological filtration, as it converts nitrates into nitrogen gas (good). Others say that sand is just for looks.
Here are all great lights for your tank (I'm going by a 10G tank)(all depends on budget): http://www.drsfostersmith.com/produc...7&pcatid=13637
Very tight budget light: http://cgi.ebay.com/New-T5ho-t5-ho-2...1.c0.m14.l1318
All I can think of right now on lights...
If you have any more questions, feel free to let us know. :)