Still a card-carrying FNG myself, but get Fenner's THE CONSCIENTIOUS MARINE AQUARIST, considered the bible. Do be aware that much of the real-world advice you get here may contradict some things Fenner says, but there's no silver bullet in this hobby.
Note that while there's ways to get into this hobby without breaking the bank, it does cost some money. The approach the Mrs and I are taking is that it's better to spend some now on the proper and high quality equipment to achieve better results, avoid as many potential problems as we can, and have an easier to maintain system.
You mentioned hard water . . . do think seriously about getting your own RO/DI water unit. True, you can buy reverse-osmosis/de-ionized water, but in the long run you'll be miles (And dollars) ahead by making it yourself. They're not really expensive and easy-sleazy to set up.
Granted, to the uninitiated salt water tanks are a bit complicated to set-up and maintain, but not once you realize what it takes. Interestingly, the vast majority of responses I get when I mention setting up a SW tank is, "Are you going to hire someone to maintain it for you?" My response, "Um, no. Seeing that I can walk and chew gum at the same time, I'm perfectly qualified." Of course, that does take some education, but it's not outside the capabilities of most people if they're willing to take their time and learn. This board is full of threads about problems brought about by people doing too much too soon.
As already mentioned, it will take some time, so that will have to be factored into your life-schedule.
Probably the greatest piece of advice I or anyone else can give you is that this endeavor requires patience, patience, and even more patience. Please do not rush into anything . . . buying equipment, getting livestock, etc. We've had our tank in our living room for close to two months, and we're just getting ready to put salt water into it. It's not that we're slacking about it, but we've examined every aspect carefully, bought prudently (And have already saved several hundreds of dollars over MSRP), and not rushed.
Good luck and welcome!
