Finding Pokemon

Each Pokemon has a particular location where they like to hide:

Red field
Pallet Town: Charmander, Rattata, Nidoran (M), and Poliwag 
Viridan Forest: Weedle, Pidgey, and Pikachu
Pewter City: Spearow, Jigglypuff, Ekans, and Magikarp
Cerulean City: Oddish, Mankey, Jynx, and Abra
Vermilion City Seaside: Shellder, Krabby, Ekans, and Farfetch'd 
Rock Mountain: Voltorbe, Diglett, and MrMime
Lavender Town: Gastly, Magnemite, Cubone, Electabuzz, and Zapdos 
Cycling Road: Spearow, Doduo, Lickitung, and Snorlax
Safari Zone: Paras, Rhyhorn, and Chansey
Seafoam Islands: Horsea, Staryu, Seel, and Articuno
Cinnabar Island: Ponyta, Growlithe, Omanyte, and Kabuto
Indigo Plateau: Machop, Onix, and Ditto 

Blue field
Viridan City: Squirtle, Nidoran (M), and Bulbasaur
Viridian Forest: Caterpie, Rattata, and Pikachu
Mt Moon: Zubat, Paras, and Clefairy
Cerulean City: Bellsprout, Meowth, Jynx, and Abra
Vermilion City Streets: Shellder, Krabby, Farfetch'd, and Sandshrew 
Rock Mountain: Diglet, Voltorbe, and MrMime
Celadon City: Mankey, Meowth, Eevee, and Porygon
Fuchsia City: Magikarp, Goldeen, Kangashan, and Exeggcute
Safari Zone: Doduo, Nidoran (F), and Chansey
Saffron City: Ekans, Sandshrew, Hitmonchan, and Hitmonlee
Cinnabar Island: Ponyta, Koffing, Aerodactyl, and Magmar
Indingo Plateau: Geodude, Ditto, Moltres, and Mewtwo

Finding Rare Pokemon

On the third ball, light up all the "GET" lights and enter the hole. This will increase the chance that rare Pokemon will appear.

Easy Pokemon Capture

Hit a Voltorb or Shellder, then hold A or B when their shadows appear.

Easy 10 Million Point Bonus

Upgrade your Pokeball all the way to a Masterball by turning on all the lights on the top half of a board. Then, try to upgrade it one more time. This is much easier than having to evolve a Pokemon with a star next to its name.

Double Cave Bonus

Light up the letters C, A, V, and E to unlock the Cave bonus, but do not enter. Light up the same letters again, then enter the Cave to collect double the amount of points.

Special Evolution Bonus

Enter evolution mode. Then get the menu and select a Pokemon that has a star. Go through the entire evolution process. After the Pokemon evolves, a special evolution bonus worth 10,000,000 will be awarded.

Easier Way To Evolve Pokemon

After entering evolution mode, quickly hit the buttons with the flashing arrows next to them. Do not try to raise Pikachu's lightning meter. The "Ball Saver" will stay lit for awhile. During this time, after hitting a button with a flashing arrow, allow the ball to move below the flippers. After the ball is launched, if the item you are looking for is near the top, you will have a good chance of getting it. Note: If this is attempted, always make sure that the "Ball Saver" is not going to run out.

Evolve Pokemon In The Blue Field

Shoot the Pokeball through the left loop. Each time the Pokeball passes through the loop, one evolution arrow will light. When all three arrows are lit, shoot your ball into Slowpoke's mouth. Then, choose the Pokemon to be evolved.