fish / starter fish: You have to seed the tank with bacteria, thus you'll need some hardy fish to start with. I'd say 2 Damsils, & a green Chromis. They wont die....no matter what- lol- trust me, I've tried killing them bastards. Downfall is, they'll kill everything in there once you start loading up on good shit - thus, your gonna have to take em out before you REALLY get started. Only keep 1.
No saltwater is "full proof", my advice is buy your water, pre-mixxed. Dunno where you stay, but a lot of stores will carry skimmed saltwater to start your tank with. If you go the old school way, you'd have to have your tank setup for at least 6 weeks before you put anything in there.
A protien skimmer / heater ( tripocal fish should set between 79 & 81 degrees ) / 2 GOOD powerheads for current / & a fluval canister filter should get you started ( unless you wanna pay HELLA money & build a backpack skimmer for your tank )
Your chem will run you about $15 a month- they have pre-mixxes for beginners - after a while, you will learn your balances, & be able to buy the chem individually, cause you'll know what you need, for what you have. But the premix stuff is great to start with. One of the most important things to have for salt, is the lights- thats probably the most expensive part too-....you have to get a 50/50 light, atenic, & a halogen as well.
My duties, now that the tank is 5 years strong ( & close to the same in the beginning ) are- feeding once a day, or course ( no flake foods either....you want to feed them brine shrimp - frozen or fresh- either way ) - once a week chemming the tank, & cleaning the view - & a 5% water change on a weekly basis. ....you can have your water checked @ the store, but I'd buy a kit for like 5 bucks if I were you, to test it yourself.
what size tank you plan on setting up?
rock is the best natural filtering system you can have- just make sure you only buy live rock & live sand. ( or live coral, if you prefer a coral base )
once you've setup the tank, & you've had it for a few months, you'll learn by trial & error, what goes with what- you'll see you can get some real sensitive type stuff ( anenomes, pollyps, starfish, soft corals, shrimps, & so on ) but it takes time to get your tank up to speed for these creatures to live in the enviroment.
Google some of the salt water message boards, & advice is abundent - & a lot of those cats on there have masters degrees in marine biology ( which I am studying for now )