Firstly make sure you have a place you can sell the fry to! Either a locally owned pet shop, or an aquarium society. Are you in the US, if so What state are you in?
Second, you'll need a 10 gal tank, and a 20 gal tank( or bigger for when the baby fish get bigger).
For the breeding tank, you'll want a small heater, a sponge filter, and a lid (Danios are jumpers). Light is not necessary, but can be used.
To make a grate for the eggs to fall through, I use needlepoint canvas, it's cheap and easy to cut to size. All craft stores should have it. Once you have it cut, place a pvc pipe or cup underneath to hold it up. You'll want the water level to be 2 inches or so above the mesh,(this way the eggs fall quickly into safety, so they don't get eaten!). Also, plant trimmings or moss at the top are great, as they like to scatter their eggs in the plants. I'd set up the tank a day before spawning (after conditioning), and cycle the sponge filter in your main tank.
Then I'd condition the adults (should be at least 6 for an even sex ratio.) with multiple, small feedings each day for about 2 weeks. Live or frozen foods are great, but flakes will work too. You can condition them in your main tank.
Now after the 2 weeks, in the evening, take the best looking male(more skinny ones) and 1-2 females(more plump, like the one in the picture) and place them into the 10G. They should spawn within 24 hours, and then remove the adults as they do eat their eggs.
The fry will hatch within 2-3 days, and I recommend feeding a prepared food, like Repashy Spawn and grow, hikari first bites, and my favorite Golden Pearls. Live foods will work too, but it's more work.
This is the general breeding idea, let me know if you any questions!