how do you get 99 rare candies in pokemon black?

Answer 1

You don't, 

 

 

 

 

 

 

 

 

 

 

 

 

 

Unless you cheat!                                        

Answer 2

As far as I'm aware of there's no method of cheating in Black/White. I'm not sure if GameSharks work with this game. However using rare candies will never be as useful as battling due to EVs and such.

Answer 3

Could use a cheat system like action replay

Answer 4

999 Rare Candies (AR)
02234624 03E70032 (press L+R)