you can get a berries by catching meoths and rattatas and seals
also you can use your itemfinder. berry forest i think its called, has a lot of berries in it. whereever berries are, there are little dark patches. they are small but you can still see them and there are a lot in berry forest.
You can't get that berry in firered.
You can't.
You can get a iapapa berry from lostelle at berry forest also possibly from a Pokemon that has the ability pickup.
berry forest
In berry woods In berry woods you must know surf to get there on 3 island
You need to link with a friend
Search around in the berry forest.
only firered and leafgreen.
You pick em up in the berry forest
The only way to use berries in FireRed and LeafGreen is to berry crush with another FireRed, LeafGreen, or Emerald using GAMEBOYS (DS wont work) and 2 wireless adapters
Only firered, leafgreen, ruby, sapphire and emerald can get a pamtre berry for firered and leafgreen you can get it from a Pokemon with the ability pickup, in ruby, sapphire and emerald talk to the berry masters wife and tell her "challenge contest" she will be impressed and give you a pamtre berry.
In Pokemon firered you can't, but in Pokemon leafgreen you can get it then trade it to Pokemon firered.