Once you’ve got all of the equipment you need to begin breeding guppies, the fun begins!

Choosing your first adult guppies that will be the beginning of your line is a process that can take some time. A vital part of breeding guppies is selecting good quality founding fish, in order to ensure that your eventual guppy lines are healthy, appealing to look at, and possess a range of desirable traits.

It is normal to start with three guppies as your breeding adults: two females and one male.

In this article we will guide you through the process of breeding guppies, from selecting your adults to raising the fry.
Step one: Choosing your founding adult guppies

While you can just pop along to a pet store or aquarium retailer that sells guppies and select attractive-looking fish, if you intend to take breeding guppies seriously, you might want to consider buying your founding stock from a professional breeder or show breeder, as they will often be able to offer a better range of options.

Look for fish that are mature and healthy, and that display the traits that you wish to produce or enhance.

Select for shape, color and pattern, and the traits that you find physically appealing, but don’t forget to make sure that the fish that you pick have good conformation and do not have any curvature of the spine or flattening of the heads, which can indicate poor quality stock.

While female guppies will never be as bright or striking to look at as males, do try to pick females that are the most physically appealing of those on offer, as the quality of the female fish will affect the subsequent males too! When you spot the fish that you like the look of and want to own, you will normally know it straight away!
Step two: Breeding guppies in the main tank

Place your two females and one male into the large tank where the adult fish will reside, and let them get on with things!

Guppies generally breed quickly and prolifically, although they may need some time to settle down in a new tank. It is not unusual for healthy breeding-age guppies to breed within 24 hours of introduction!

When the females and males are together, provide a highly nutritious food to encourage breeding, and keep the tank temperature at around 25-26 degrees Celsius.
Step three: Recognizing conception in guppies

It is easy to spot when a female guppy has conceived, as she has an area on the abdomen just above the fin that is known as the “gravid spot.” This is where her eggs are situated, and after fertilization, this area becomes noticeably darker.
Step four: And wait…

The period of gestation of the guppy is between 26 and 31 days, with the average being 28 days from fertilization.

During this time, the stomach will grow larger and darker, and take on a boxy rather than round appearance. If your female guppies keep still for long enough and you can look closely, you may even be able to spot the fry within the abdomen!
Step five: Moving your female guppies to a breeding tank

Once the time of delivery comes nearer, you will need to move each of your females into their own breeding tank, so that you will be able to identify which fry are produce by which female.
Step six: Labor

If you intend to use a breeding trap or partition off the tank for delivery, put this into place as the time to give birth grows nearer.

You can usually judge when the time is at hand, as the female guppy will become much less active and tend to hide, and you may even observe the contractions, which appear like a shivering movement through the body.

She may also like to stay around the tank heater, and stop eating in the hours immediately leading up to the birth.

You may want to check out this video of a guppy giving birth!
Step seven: Care for your new guppy fry!

The time it takes to deliver the fry can vary, as will the amount of fry produced. Anything from 5 to 50 live young is normal, although not all of these will necessarily make it to maturity.

After the fry have been born, it is important to care for them properly and give them every chance to survive, by providing plenty of foliage and cover in the tank to keep the female guppy from eating them. You can also protect the fry by placing the female guppy back into your main tank after the birth, although she may become pregnant again in short order.

You can also partition off your breeding tank to keep the fry safe until they grow too large to be eaten by the other fish, or make provision for plenty of plants and hiding places for the fry.

source : http://guppyfishcare.com/breeding-guppies-easy-steps/