Well I guess I had to post it, a Chocobo Breeding Guide, no FF7 page is complete without one. Now, you want the best the golden chocobo, just follow the guide.

To breed a Green OR Blue chocobo:
First, get two very good chocobo's from the Mideel or Rocket town area. Next, get a Carob nut from the Brachioladus enemies in the Icicle area. You might want to raise the classes on the parents first, so that it won't take so long to breed the right one. Finally, breed the two chocobos with the carob nut, and you have yourself either a green, mountain chocobo, or a blue, river chocobo.

To Get a Black Chocobo:
Breed a green, mountain chocobo with a blue, river chocobo, with any nut (it makes absolutly no difference). you will get a black chocobo that can go over mountains and shallow rivers.

To get a Gold Chocobo:
Breed a black chocobo with a Wonderful chocobo, which can only be found in the icicle area. Use a Zeio nut. These nuts can only be won ar stolen from the goblins on goblin island (an island on the east world map, that has a forest on it). You almost have to get the parents up to class A or S to get one, since they are very hard to breed.

The Classes:
Classes are gained on your chocobo by going to the gold saucer, and talking to Ester (she is on the left side of the chocobo racing place). After a few races in one class, you will move up a class. The higher your class, the higher the probability there is for you to breed a chocobo mutation (ex: green, gold, black)