Pokemon Heart Gold and Soul Silver - Walkthrough - Goldenrod City Pokemon Heart Gold and Soul Silver: Walkthrough - Goldenrod City
There is a lot to do here! I advise you check every building in this city to see what you can get, I'll give you a brief run through, as some of the items are not required for story progression, but certainly will be convenient!

So first things first, go to the Pokemon Center and heal up!

After that, visit the DEPARTMENT STORE, on the right, the tall building. You can buy a lot here, you can check the LOCATION section of my guide for details. There is also a man offering a MACHOP for a DROWZEE, so trade with him if you want.

If you take the elevator to the basement, you can obtain some items that are lying around. They are an ULTRA BALL, an ETHER, and a BURN HEAL. You have to talk to the people there to get their MACHOKE to move the containers out of the way.

Back out of the DEPARTMENT STORE, head northwest to the GAME CORNER, and go inside and talk to the man on the chair. He will give you a COIN CASE when you say "Yes." You can play his mini-game if you want.

Outside again, go to the northeast part of the city with a boy who talks about a BIKE SHOP. Follow the winding path downward and eventually you will come across it. Go inside and speak to the man to receive the BICYCLE! Even faster than the running shoes.

Now go to the northwest part of the city, where there is a black building. This is the RADIO TOWER, with a TEAM ROCKET member standing outside of it.

Go inside and talk to the lady on the far right side of the counter to begin the QUIZ to acquire a RADIO CARD.

The answers are (in this order):

Question: "Can you check the Town Map with your Pokegear?"
Answer: YES

Question: "NIDORINA can only be female. True?"
Answer: YES

Question: "Kurt, the Poke Ball creator, uses apricots as ingredients?"
Answer: NO

Question: "It's impossible to use a TM on MAGIKARP. True?"
Answer: YES

Question: "In Professor Oak's popular show, Pokemon Talk, is he on with Mary?"
Answer: NO

You will now be able to listen to the RADIO on your POKEGEAR. Also, you just got GYM LEADER WHITNEY to go back to her GYM!

Go upstairs and talk to BUENA if you want the BLUE CARD (she is on the bottom right of the second floor.)

On your way out, try your luck with the LOTTERY, you just may win something!

Take note of the GLOBAL TERMINAL to the west here. It is not story relevant, but can certainly help you out!

Now to continue with the story, go north under the bridge and you will see a building next to a funny looking tent. (This tent has the NAME RATER in it.)

Go inside the UNDERGROUND ENTRANCE (to the left of the tent).
This walkthrough was written by MKaykitkats, used with permission.