You go through Petalburg Woods. You come out the other side in front of the Pretty Petal Flower Shop, on Route 104. Once you've won your first Double Battle, you can finally get to Rustboro City.
Rustboro City Edit
When you're at Rustboro City, don't forget to admire the view. You'll see that Littleroot is nothing compared to this massive port! Having the Trainers school, the Cutter's House where the Cutter himself will give you TM01 Cut (but it can only be used outside of battle if the Trainer has earned the Stone Badge), the first Pokémon Gym where you can earn the Stone Badge from Roxanne if you defeat her (the Stone Badge enables you to use TM01 Cut outside of battle, and all Pokémon up to Level 20 will obey your every command), and not to forget the Devon Corporation, where we will be going next.
TIP: There is a cheat way round the Rustboro City gym. I'm sure you'll all find it anyway!
At the Devon Corporation, an officer will take you to the top floor. There you will meet Mr Joseph Stone, president of the Devon Corporation. He will give you a new tool. Please edit the page if you know what that is!!! He will send you to Dewford Town, and he will ask his old friend at Route 104 to sail you to Dewford, and that is where we are heading! Oh, and also, the task is to give a letter to Steven, another old pal.
Dewford Town Edit
Once you reach Dewford, you'll find it is a very quiet town. Dewford is very unusual, though, as it is not on Hoenn land. It is actually overseas.