Chain 40 of the same Pokemon
You can find shiny Pokemon randomly through out the game.
To get a shiny Pokemon try using the poke radar
In the underground.
You can find rare Pokemon from other games and even shiny Pokemon! I found a Shiny Hippopotus once :P
You can find a Shiny Stone in Route 228 in Pokemon Diamond and Pearl. In Pokemon Platinum, you can also find a Shiny Stone on Iron Island.
Togapi is in the only grass on rt. 230. You have to use the poke rader to find Togapi. Togapi will evolve when it grows a level and has full happiness. Togatic evolves when you use a shiny stone on it.
You can only catch bagon in pearl. But you can catch larvitar, route 207, you have to use the poke rader. If you had pearl you would find bagon on route 210 (fog) with the poke rader.
you don't need a ar code to catch and keep shiny Pokemon in Pokemon pearl all you need to do is find the shiny Pokemon you want and catch it and unless you release it you keep it.
you sometimes find them in the wild
anywhere where you find a normal shiny. shinies are exacty the same but rarer.
Try using the pokeradar, its not perfect but it could lead you to a find.
The easiest way is to use the Poke'Radar.