You need to buy some eggs. I bought mine through www.aquabid.com. Its a good sized can so it will last forever for you (may be even too big if you don't need constant feeding).
I made by own DIY hatchery using a 2L coke bottle.
1. Cut off the top 1/3 of the bottle.
2. Take the cap, put a hole through it, insert the end of a air tube. This needs to be connected to a air pump, of course.
3. Put the cap back into the top third of the bottle.
4. Reverse & insert the top third into the bottom two third. (Putting some rocks in the bottom bottle may help to keep the setting stable).
5. Put some water, some marine salt, and baking soda. (I use about 1/2 tea spoon). You can use the tap water directly - chlorine will go away.
6. Turn on the air tube lightly so that you will see few bubbles of air coming out every second.
7. Wait for two days. (Make sure the room is not too cold, colder the room is slower they hatch).
8. You will observe lots of bright orange dust-like articles in the water. Shine a tabletop light towards the mouth of the bottle where the cap is. Keep it there for few minutes.
9. Use a baster or syringe to suck them out. Use a coffee filter and some plastic cups to filter these critters off. Feed these to the fishes...
I know it sounds like there's alot of steps, but you get used to it. It takes no more tha few minutes of your daily life to feed multiple tanks of fishes. Also given the size of the can, I figure this must be one of the cheapest food I can get for the fishes!
Try it if you feel you are up to it...