All the above is good advice. Just to underline the key thing is STABLE good quality water. Not mentioned above is a raised temperature. 82 a minimum, 84 is preferable.
Now, a stable environment in the aquarium can only be maintained by regular water changes.
Sounds an obvious statement, yes, but what I'm trying to convey, and I'll do it on a few fronts, is the importance of not stressing discus. Stress will manifest itself in many ways. Turning the lights on in a darkened room for example will have them darting manically for cover , often bumping into anything in their way. So I have a small table lamp on a timer that comes on at 6am to replicate dawn, this then allows me to put the room light on at 6:30 to feed them before I head off to work.
Messing around in the tank too much also bothers the less confident fish in the group, they'll often then hide for a couple of hours. So, on that front I'd advise aquascaping and planting so that you're happy with the tank before adding your discus.
I'm not a fan of live foods, not worth the bother or risk. You can get all,the nutrition and protein required from discus pellets, my favourite is prima, and quality frozen foods including discus specific preparations.
Now, back to water. De-chlorinated tap water simply isn't good enough. You'll need an HMA filter to draw off your water. Then it will need both the temperature and ph matching to that of the tank. I do 2 75ltr changes each week with a heater and small circulation pump in each bucket., overnight. The ph is then matched with acid added. Discus are sensitive to both sudden temperature or ph swings.
Quality, reliable filtration is important also. I prefer to use 2 externals so that, hopefully, I'll never be without one. I clean them alternatively and have Purigen in both to keep down organic waste which helps keep nitrate down. Now that set up of mine certainly isn't crucial, but it gives me peace of mind, however the water quality it gives works as a pair formed and now they have regular spawns.
If you were to have a group of six, probably a minimum to keep, please don't panic or be too concerned if a "runt of the litter" appears, getting bullied a little more developing more more slowly than the others, its just part of the natural pecking order that happens within the group.
Keep a good surface agitation, the increased temperature can mean lower oxygen saturation, and avoid strong currents.
All that said, enjoy the king of the freshwater aquarium, they're worth the effort,and fantastically rewarding.