First, be sure you have the correct types of chocobos. If your chocobos are either good, great, and wonderful, you'll have what you need to make a gold chocobo. You will also want to race your chocobos frequently at the Golden Saucer. Be sure all of your breeding chocobos are Class S (they will become this once you've won enough races.)
Well, you'll definitely need some chocobo food, right? You can buy all sorts of greens for the chocobos you have caught to eat at the chocobo farm. If you found the chocobo Sage's house in the mountains above bone Village, the Sage will sell you Sylkis Greens and Reagan Greens. You'll definitely want to stock up on those. But you'll need certain nuts when you are breeding as well. You can't buy nuts--you'll have to steal Carob nuts from Vlakorados, which are found in the area near Bone Village. Zeio nuts, which are used when you breed a Gold chocobo, are found by stealing from Goblins that are found on a small island northeast of Chocobo ranch.
Now for the breeding process, which must be done in the following order:
Mate a Great or Good Class S Chocobo using a Carob nut--Green or Blue
Repeat process to get another special chocobo, blue or green, depending on the one you recently bred.
Mate a Class S Green Chocobo with a Class S Blue Chocobo using a carob nut to get a Black Chocobo.
Mate a Class S Black Chocobo with a Class S Wonderful Chocobo to get the long awaited Gold Chocobo! But it takes a reeeaaally long time...HOWEVER, it is worth every minute of your labor when you get to blow Jenova-SYNTHESIS away with a single "Knights of the Round" Summon...Oh, wow, that was great!! And it'll kill Bizarro Sephiroth and Safer-Sephiroth quickly, too...not as quickly, but quick enough if you're good! ^_^
Hope that helped! By the way, love the signature, Kiwi! RuroKen RULES!!
@.@ - Ororororo....