OK .. I'll try to describe it.
Let's say you are holding the console opened with your hands ready to press the buttons.
On the left, there is the Control Pad.
Up right of the pad, there is a small button, that's the On/off Switch for the screen.
Straight right from the control pad, there are the B button, then the A (a little bit higher).
Down in the middle, there are the Select (left) and Start (right) button.
They are just under the speaker, so you should have an easy time to feel/spot them.
On the two sides, behind the hinges, it's the L and R shoulder buttons (L for left shoulder, R for the right shoulder).
Finally, there are two switches on the side of the console.
On the left side, away from the cartidge slot (around where your left index might be resting), there is the volume sliding switch. "Loud" is up/away from you.
On the right side, near the cartridge slot (where you right hand palm is) there is the on/off switch for the console. "On" is up/away from you.