Here are a few tips that might help:
1.) Before you get a tank set up for livebearers you should always keep in mind the amount that they breed. When males and females get together they will start breeding almost inatantly. The females have fry every six weeks, the amount of fry they can have ranges from 10-35. But in some cases I've herd they can have up to 70 young in one broad! So before you think of putting males with females you should also have in mind a rearing tank for the fry.
But I have 40 babies in my tank, they are medium sized about 2cm in a 60L, now I have to buy a 215L to put the babies in!
2.) Livebearers need a hight vegetable diet (guppies,mollies and platies). So a good idea would be to feed them tetra pro vegetable or something like that. Livebearers also need to have a lot of live food, you should feed them twice a week, or more. But fry and baby fish sould get live food more often, frozen or live it doesn't really matter.
3.) Selective breeding of guppies.
Ground and cover colours: In addition to fin and tail shape, colours play a very important part in selective breeding.
Guppies have a basic or ground colour on which are markings in other bright and iridescent cover colours that catch you attention. The most important ground colours of guppies are: Wild-colour, Albino blond and blue.
Wild-colour guppies have a grey or olive-green ground colours.
Albinos lack black pigments so there bodys are light coloured and there eyes are red.
Blond guppies also have light coloured bodies but the black pigments are not completely lacking.
Blue guppies lack shade of yellow and red and because of this they have a blue shimmer.
By combinining these different colours new ground colours can be created.
4.) Raising the fry
If you want to raise fry it is advised to put them in a rearing tank, they will be in the rearing tank until they are big enough to not be eaten by the adults. When they reach this size (by about 6 months or more) they should be put in the tank with the adults. For raising fry they will grow better if raised on proper fry food. This is because of the nutrition in the fry food is different to the adult food, fry need a higher protien requirement to grow so there is more protien in the fry food. Fry can be raised on adult flake but they will not grow as well. Live or frozen food is also important to fry to grow so you should feed them something like daphnia or baby brine shrimp.