Generally you don't want to keep several species together in order to prevent crossbreeding. Each species comes from a different locale.
As far as care, they like temps to be in the lower/mid 80's. Too hot will bake them. They don't have any special lighting/heating requirements if room temps are 'normal'. The only light we have on the terrarium of our
dendrobates tinctorius is a plant light. They require no standing water, just good humidity. Water falls are good for breeding, but unnecessary in general keeping. I would suggest speaking with Sarah and Melissa of
Quality Captives for more specific information.