Things like temperature, environment, and diet have been covered on the forums, though I suppose the latter being the less covered. Temperatures should be around 78-97, with humidity around 30%. As long as you have water crystals in there, or moisture rich foods (like carrots, etc) the humidity should take care of itself with those temperatures. Make sure to put the screen more over the food side so that the air and moisture escapes on that side to not only help prevent mold (mold will kill a colony in an instant), but to also avoid the ""housing side"" from having too much light.
Some people if they live in a warm climate do not need to heat their tub, but I personally do despite living in a warm climate. I just turn off the heating pad whenever I notice the ambient temperature is getting too hot in the tub. Human heating pads are better for this job since reptile heating pads get too hot. You can also use heat tape but I have NO idea about that haha. I do know that a lot of people on this forum, a few others, and myself use
this heating pad. You want to place it under the egg crate houses. The idea is it'll heat them up all good and toasty but if they decide it's too hot they can either climb higher up the egg crates, or go to the food side.
Speaking for food, on the topic now of food and diet. They're cockroaches. They will eat scrappies so long as there isn't mold present, because again, mold is the kryptonite of dubia. Dubia need a high protein diet, and maybe somebody will come in with some information on "roach chow" recipes. Or maybe even a google search can help out. For me, I use fish flakes, cichlid pellets, and occasionally ground up cat food for protein and they enjoy it. Once I have more time I'm pretty sure I'll come up with a really cool roach chow, but for now I just feed them that but I also feed them a lot of fruits and vegetables! The other day I was making sweet potato chips so i gave them the skin shavings and a couple normal shavings and they ate them up fast. My colony also enjoys strawberries, grapes, carrot, and the leaves on celery stalks. An important note, even though calcium is good for your reptiles, do not feed your dubia calcium. Only dust them, or if you have a separated feeder bin, you could try to feed them the calcium in there.
Dubia roaches appear to really enjoy citrus, especially sweet citrus. Oranges, clementines, tangerines.. Mine will sometimes eat grapefruit but I think it's too bitter. A lot of people swear by citrus promoting crazy breeding, I personally haven't seen it but my colony is still kind of new. I just think it's the cutest thing in the world whenever I see teenage dubia taking of pieces of the pulp and walking away with it haha.
I hope this clears some things up?? There are a lot of good resources, there's one forum on the front page called "for the dubia know it alls" that has information in bullet point form, very clear. If I had some more time I'd add some links to some good threads/websites, but for now this will have to do!! I'll probably compile a list tomorrow.
Good luck!