Oh boy, where to start... Welcome to Salt Water! I guess we can start with size. Are you restricted to the ten gal, or can you go bigger (20, 30-50+ gal). Do you have a large amount of cash? Do you have time to do 10-20% water changes every other day or so? Can you check the water every day? Do you expect the tank to be done within a month? Do you have experience with fresh water?
Equitment: Skimmer ($100-600, i think), Lights (for corals $500), Tank itself($50-200), filter ($50-100), Sump (second tank near the first one, connected by tubes to the first one, with some extra stuff, $200), test set ($50-200),heater($50-100), power head($20-120). Live rock isnt really under equitment, but without it you will have a very hard time keeping a small SW tank ($5.99-12.99, advantage) Price will vary.
And now we get to the animals.
# Fish:The only nice fish i can think of that can live in a 10 gal would be firefish, and gobys. You couldnt get a Clownfish unless you upped the size to a 20 or more.
#Corals: need really good light, and at least 1 powerhead for current. Corals also need special foods, suplements, and addatives, and do not tolerate copper in any form.
# Anenomys: Need to be fed food, can eat fish, need good lights, need addatives, cant tolerate coppers, need mature tank, preferably around 9 months to a year old.
#Shrimp: Need a stable tank.
#Crabs/Hermints: Need food, can be bad to corals, are scavengers and will eat other critters if starving.
#Hitchhikers: Come in with live rock, can be problematic, usually good for tank. Problematic hitchhikers include (but are not limited to) Pistol shrimp(eat fish), glass anemone (can also eat fish, take over tank, kill with peppermint shrimp, usually), crabs (can eat fish, corals, snails), other (many others can be bad). Good fellas: Sponges and filter feeders (clean water in tank, can also tell you when you are overfeeding fish), Bristle worms (can bite, but also clean bottom and sand in tank. Will not hurt fish), small starfish (clean tank of food) other (many other good fellas can come in with live rock).
And now we get to the "what is live rock" part. Live rock is rock that comes from the ocean, complete with bacteria, corals, sponges, other, which filters your tank. Live rock is the tanks biological filtration. Very helpfull, stabalizes tank and starts cycle. Do not try to take live rock directly from the ocean, thats illegal, stupid(it could have pollutants in it), and danger use. You never know what could be hiding in it (fish that bite, stinging critters, large crabs). Its just safer and easier to buy it from the LFS.
The Cycle is when your tank has a spike of ammonia, then nitrates, then nitrites (or nitrites then nitrates, cant remember which comes first). The cycle WILL happen, so dont get any fish until it is over. Just go the the market and buy some frozen shrimp that you would normally eat, and put it in the tank. That will start your cycle as it decays. Live rock can and will help hasten the cycle.
The sand in your tank (if you get sand) will eventually become live sand, and will add to your biological filtration. Sand will take time to become live.
You will have problems, you will get hitchhikers, and it will take time and effort to get a SW tank running. Just remember that you can always ask for help from us, and that as long as you don't give up you will get your own tank up and running. Good luck and i hope this helped!