The controls of the game aren't very complicated, making the game fairly easy. Below are the controls for doing certain things like grabbing items, looking in certain directions, speaking to Pikachu, and other things.

Start button
Pressing start opens up the PokeHelper and close it at the beginning of the game and during fishing levels. When you get the toolbox, pressing the Start button will open the toolbox and close it.

A button
When you're near an item, press A to grab it, or if you have an item, press A to throw it. When you are in the toolbox, press A to put in or take out an item in the toolbox. Also press A to confirm messages from descriptions of items and from people like your Mom or Prof. Oak says.

B button
Press the B button when you're near an item to get a description of it. When you're looking at the PokeHelper press B to go back to previous menus. Also press B to close the toolbox.

Z button
One of the most important buttons in the entire game. You press and hold the Z button to talk to Pikachu. Let go of the Z button to send what you said to Pikachu via a bubble. Make sure that when you're holding Z and speaking to Pikachu that you speak clearly and slowly into the microphone or Pikachu won't get what you said. =)

C left button
Press or hold C left to look left.

C right button
Press or hold C right to look right.

C down button
This activates the View Mode, which you'll receive from Professor Oak when you get good at the game. =P When in view mode, use the control stick to change your view. You can easily grab Pikachu's attention with this. When you want Pikachu to look at a certain item, press C down and use the control stick to point to an item, then hold Z to call to Pikachu. Say the name of the item (if you don't know how, look up at the B button description) and Pikachu should go to it and do something.

C up button
Press this to enter Pikachu Mode, which you'll also receive when you're good at the game. This lets you look in the direction that Pikachu stands. You won't have to manually look where Pikachu is, saving you some time.

Control Stick
Tilt this in several directions to move around or look about.