In Fuchsia City in the house next to the Safari Zone warden's house, there is a fisherman who will give you a good rod.
Below Lavender Town there is a big pathway on the water. There is a house that is just a little bit below where you can find Snorlax, and the fisherman will give you a super rod.
And finally you can find the old rod in the house next to the Pokemon Center in Vermilion city.
Hope this helps :D