How do you trade Pokemon from Ruby/Sapphire?

Go to the second floor of a Pokemon center and talk to the ladies one will give you a choice to use the link cable or you might be able to use the Wireless but I'm not sure. I haven't tried.

To Trade you must get the Ruby and the Sapphire gems and give them to Celio. To get the ruby go into the mountains on Island 1 and fight the Team Rocket grunts. Then go into the cave and look around for the ruby gem. When you get it go out and give it to Celio. He will give you the Rainbow ticket. Use that to get to different islands. On another islands (I forget which one) the is a place called Dotted Hole. There is a door there that has dotts on it. Use Cut on the door to get in. inside is some holes. here is the order to drop into them.

North
West
East
South

There you will find Sapphire.
A scientist will take it. The go to the team rockets wharehouse (on another Island) and go in. inside is the scientist who has the Sapphire gem. give it Celio and enjoy trading!

Well frist you have to give the Ruby and the Sapphire to Cileo and now you can Trade with Ruby and Sapphire but you can not use the Wireless adaptor you need the trad link.