Not hard to keep, but not for the novice. The maintenance is time consuming but IMHO well worth the results and if you want the best for them. As mentioned by 86 ssinit take a look at that thread along with this one. Discus Gang Updates | Discus Fish Forum | 420110
A ton of info from beginner to veteran keepers.
I kept them for almost 2 years it was a journey, I started with 6 juveniles in 55g. Maybe again in the future, but at least this time I will be far more prepared.