1. Start in the game as a boy of 10 in your room... Head to the tall grass north of town... Listen to Professor Oak as he tells you that the tall grass is dangerous, and that you need your own Pokemon for protection... Follow him to the back of his lab, where your Rival is waiting... Listen to Oak talk about fulfilling his dreams... Pick a Pokemon: Charmander, Bulbasaur, Squirtle. Choose carefully...
2. Battle your Rival, who challenges you on the way out...
3. Head through the Tall Grass to start your adventure!
4. Walk through the Tall Grass, but be careful, as there are many wild Pokemon waiting to battle you! When you finally reach Viridian City, you should first stop at the Building labled "POKE". This is a Pokemon Center, that heals your Pokemon for free! There is one in every town, so make sure you keep your Pokemon at good health. The next stop you should make is the Pokemart, which says "MART" on the outside. The cashier will talk to you, asking you to take a Parcel to Professor Oak. Guess you have to go back...
5. Go to Oak's Lab when you reach Pallet Town. He will take the Parcel from you, and then your Rival will come in. Professor Oak doesn't remember asking him to come, but then he remembers. He has something to give both of you. After a bunch of talking, he gives you your Pokedex, an Electronic Pokemon Encyclopedia. Take it, and after more talking, leave, and head back to Viridian City...
6. Go to the Pokemart and buy Pokeballs, which let you capture Pokemon. Now, if you want, you can go into some Tall Grass and capture a Pokemon!
7. Begin capturing Pokemon. It's easy! First, have one of your Pokemon battle the Pokemon, but be careful not to faint it! Just put it down to low health, then hit the "ITEM" button. IT will show you a list of all your Items. Hit Pokeball, and it will probably capture the Pokemon. If not, try again, or weaken it some more.
8. Finish capturing Pokemon, etc., then head North from Viridian, and continue your Journey. Look out Pewter City, here you come!