You say that I can get the legendary beasts. Depending on my starter Pokemon..

1) You have to search them out in grass routes of Kanto. There will only be one, as said before, depending on your Starter.

2) First of all, that is Pok�mon Emerald only, so that question should be asked in the Emerald page, not here. Second, capture all 202 Hoenn Pok�mon, not ALL Pok�mon.

Sorry for when I said that all the Hoenn Pokemon. I mean only in Pokemon Emerald Version, if you get all the Hoenn Pokemon you can get a Starter.

The Dog you get is extremely random. They lurk all around Kanto, I hate to say it, but stock up on Repels and walk around the Grassy areas.

Squirtle = Raikou
Bulbasaur = Entei
Charmender = Suicune

After you beat the elite 4, It will start roaming around Kanto..Only Kanto not Sevii Islands...If you pick Char as your Starter then you will get Suicune..

To catch a legendary "beast" you must first defeat the Elite Four. Once you've done that, catch 60 Pokemon from ANY region, this means any 60 pokemon. Now get the National Pokedex from Proffesor Oak, and go searching. Depending on who you started with, you'll get a different "beast" If you started with Charmander, you'll get Suicune. If you started with Squirtle, you'll get Raikou. And if you started with Bulbasaur, you'll get Entei. Good luck, this is the REAL way to get the "beasts".

1-The beast you will find is always super-effective against your Starter:if you chose Squirtle(water),Raikou(electric) appear,Charmander(fire)=Suicune(water) and Bulbasaur(grass)=Entei(fire).It will appear in Kanto(it will NOT appear in the Sevii Islands or caves).
2-To get them,you only need to have the national dex(bet the elite4,have 60 pkmns caught and talk to oak).I'm not sure if you need to complete the machine task in One Island,but I think not.
PS:To get all the three,capture one and Trade the others from other FR/LG or trade all the three from Coloseum.