Quit it with arrays!
All you need to do is track where to mouse goes when you push the mouse button over the picture box. And then draw those pixels.
Now you want to get when the person presses the mouse, and when they move the mouse, so the same code goes in both the mouseDown and mouseClick events...
Add a picturebox called picMain to your form
Code:
Private Sub picMain_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single)
If Button = 1 Then
picMain.PSet (X, Y), vbBlack
End If
End Sub
Button = 1 [this is the left mouse button]
.PSet draws a pixel, X, Y are coords, vbBlack takes the place of whatever colour you want there... Make that a variable, and get the user to select the colour from a common dialog (the colourpicker one...)
yay... very primitive... very...