A great book to start with that is very well known is the Conscientious Marine Aquarist by Bob Fenner. It has a lot of information about your various choices for setup and design, as well as profiles on common choices for fish. If you are planning on starting with a reef tank, I would also consider The Natural Reef Aquarium.
The internet is good too. As I'm sure you've heard before, keep researching before you make any permanent decisions. It's hard to be patient sometimes, but I can see decisions that I made that I wish I had considered longer, one of which being the size of my tank (40g). If you have not already commited to a certain size tank, I would reccomend at least a 55 gallon, if not larger. At first it may more costly and such, but once you have everything in place, the larger the tank the more stable it will be as far as water chemistry and such, and it will allow you MUCH more freedom to include livestock that you want. Please keep asking questions.