He is in Goldenrod City.
Lickitung
Bill does not appear in Pokemon diamond and pearl, he is mentioned by bebe( the computer person in hearthome). Bill is the computer in Pokemon Gold and Silver.
At his mom's house in Goldenrod.
near the cape
kecleon
i dont have a clue
Bill will give it to you in goldenrod city I think
you smell
Take an oddish to Bill's grandfather on route 25
You can't get under bill's house.
You can get it on Route 25 from Bill's grandfather.
Show Bill's grandpa a Pichu, and he'll give it to you.