Glofish are Zebra Danios, which are egg scatterers. You'll need a marbled-bottomed tank and a few females for every male. There are more specifics about breeding danios in the sticky at the top of this forum.
However, be aware that 'glofish' are genetically modified and it is illegal to breed them as they are patented. It's also likely to be more difficult to achieve, although some have had success, others say they are sterile.
They are also illegal to buy in some places. They also stir up quite mixed feelings in forums. I personally think they're horrendous.
I do have mixed feeling about it but It was a present for my birthday.... what can i say" I dont want them bring them back"? but thanks for the info on the pattents and all