Tooltips are probably a good solution to what you want. They wouldn't
go into much detail like 'What's This', but they should give a short
description of what the control does.
You can give each control a tooltip (what you get when you hold
the mouse over the control) by adding a Tooltip control to your form,
and then in the Form's constructor (or the Form_Load event), you
can use code such as the following:
Visual Basic:
With ToolTip1
.SetToolTip(Button1, "This is a tooltip")
.SetToolTip(Button2, "This is another tooltip")
End With
Then the control 'Button1' will have the tooltip text "This is a
tooltip", and the control 'Button2' will have the tooltip text "This is
another tooltip". You could use resource files and XML to store all
of the tooltip strings and controls and then automate the tooltips
if you wanted, but if there are not too many controls you want to
have tooltips, this way would be the easiest.