Where can I find: Flash, Fly, Surf and Strength?

Flash- Go through Diglett's Cave from Vermillion City. Then when you get out of the cave, go down and you should see a big building. Go in there, talk to Oak's Aide and he'll give you the flash HM.

Fly- Go to Celadon City. Beat the Snorlax then go to the bush and use cut. Go up then left. Through the building and you'll find a house. Go in the house and the lady will give you the fly HM.

Surf- Find it in the Safari Zone in Fuscia City. It's a certain house. Talk to the guy and he'll give the surf HM.

Strength- Find Warden's Teeth in the Safari Zone and return them to the Warden. He will then give you the strength HM.

Next time, just say you want all the HM's locations.

Surf- reach the Secret House in the Safari Zone.
Strength- retrieve the Golden Teeth from the Safari Zone and give them to the Warden.
Flash- you get this from an Aide after you leave Diglett's Cave, I believe.
Fly- you get this from some celebrity who is hiding in her house around one of those routed double-decker buildings.