Arcticuno, Zapdos, and Moltres
When you have reached the mystical bird (Arcticuno, Zapdos, and Moltres), save the game before going into battle. This will allow you to restart if you knock them out or run away.

Catch Wild Pokemon Easily:
When in battle against a wild pokemon throw the pokeball at the pokemon then just as it explodes press and hold the B button.Then the pokemon should be yours!
*Note: This cheat does not work all the time, and some pokemon may need stronger pokeballs and some need to be put to sleep, sutch as Mewtwo or Zapdos!

Pikachu surfing mini-game
*Note: The Pokemon Stadium game on the Nintendo 64 is required for this trick. Successfully complete the tournament mode on Pokemon Stadium without using any rented Pokemon. Then, transfer Pikachu to the Pokemon: Yellow Edition cartridge to play the Pikachu surfing mini-game.

Printing Pokemon
Your Pokemon can be printed at the Pokemon Club in Vermilion City.

Beating Brock
Catch a Caterpie in Viridian Forest. Advance it to level 7 and he will evolve into a Metapod. Advance it to level 11 and it will evolve into a Butterfree. Butterfree can beat JR. Trainer and Geodude. Butterfree will have to be at least level 13 before it can beat Brock. Note: Use your Pikachu's tail whip to lower their defense.

Jesse and James locations
To find these team rocket members, go to these locations:

Mt. Moon (before you exit)
Celadon game corner (before you face Giovanni)
Pokemon tower, Lavender Town (before you rescue Mr. Fuji)
Sliph Co. (before facing Giovanni again, and before you get a Master Ball)

Bulbasaur
Bulbasaur can be found at Cerulean City, near the Pokecenter.

Charmander
Charmander can be found at Route 24 N.W.

Farfetch'd
Farfetch'd can be found on Routes 12 and 13.

Magnemite
Magnemite can be found in grass before the rock tunnel entrance.

SQUIRTLE
Get the Thunder Badge on the S.S. St. Anne, then go to Vermilion City to find Squirtle