How to Breed Guppies and Raise Young
Tank and Fish
First, you need a properly set up tank. You can find instructions on that in my other article called How to Successfully Set Up a Fish Tank. You will also need at least 1 male and 1 female guppy. If you want more, do not get more males than females. It is best to have 2 females for every male.
Supplies for Fry Safety
There are many ways to do this. One option is a Breeder net. Another is a different tank. The more risky option is just keeping the fish in the tank. I will get into that a little later. I personally recommend the breeder net. It is the safest option.
it is pretty simple. You just need to feed them once a day and wait. It should take about 3 months. Take good care of them, and clean the tank often. For more information on cleaning, see my other article called "How to Properly Clean a Fish Tank." It can also help if you turn up the heat a few degrees. Once you see guppy fry, you can move on to the next step.
Now that you can see fry, turn off the filter. Normally fry don't get sucked up in it, but you don't want to take chances. Now what happens next depends on what you chose above in fry safety. If you chose to leave them in the tank, turn back on the filter and you can skip this step. Just don't be surprised if no fry end up to adulthood. If you chose the breeder net, what you need to do is catch the fry with a hand net, and put them in the breeder net. The net needs to be hanging on the tank, so the net is in the inside. You may need to take the decor out to catch the fry. If you have a different tank, you need to have a sponge filter instead of a regular filter. You can transfer the fry with your net. You may need to take the decorations out to do this also. Make sure the water temperature is the same.
Now you just need to feed them crushed up flake food and take care of them normally. You can use color enhancing food to boost their colors while they grow up. When they get big enough to not be eaten by the parents, you can move them to the main tank. You want to do it before the older fry get big enough to eat new fry. This will probably be once they are about 1/2 inch to 3/4 inch. The mother will probably give fry every 3 or 4 months. Just repeat the process. Once you have many guppies in the main tank, you will be getting a lot of guppy fry.
Now you know how to breed guppies and raise fry. All that is left is to do it. If you succeed I would love to see pictures in the comments. This is the same basic principal when you are breeding mollies, platys, and most other live bearers.