In Mahogany Town buy a RageCandy Bar from the man guarding the exit. Now go Goldenrod City and ruin Team Rocket's Plans (check the link for helphttp://wiki.answers.com/Q/How_do_tou_get_in_to_the_radio_station_in_pokemon_heart_gold). When you defeat them, the man that you bought the candy bar from will let you through, now you should be able to get to Blackthorn City to battle them.
You don't have to buy anything from that man, but if you want his candy bars stock up- he won't be selling them after you beat Team Rocket. If you talk to him he will say he's out of stock. They're not that useful anyways.
dragon denyou can find dratini by surfing in dragon's den in blackthorn city. (the city where you get the eighth gym badge)
you capture the ledgon dariy Pokemon
go to the next gym leader.
Go to the forth gym!
beat the league
there is no 9th gym
After the eighth gym? Or after Pokemon league? well, for eighth gym, i recommend.. I got nothing, but for after Pokemon leagu, they give little exp, so Red.
Clair and she is the leader of blackthorn city or if you mean the kanto leader its blue/Gary ashes rivle
You CAN NOT become a Gym Leader in Pokemon HeartGold and SoulSilver or ANY MAIN SERIES POKEMON GAME.
dragon denyou can find dratini by surfing in dragon's den in blackthorn city. (the city where you get the eighth gym badge)
Capture Ho-oh. Not sure of the way to do that, as I have SoulSilver, but I know it has something to do with Ecurteak city and the Tin Tower.
Go through Ice Path on Route 44
you capture the ledgon dariy Pokemon
Defeat the eighth gym leader.
walk in
in sootoplis
The gym is in Blackthorn City.The gym leader is Clair.