setHelpInfo is used to set the contextual help informaiton for the page you are about to display. It should be called just before the display function. It looks something like this:

$gTikiSystem->setHelpInfo('Features','Settings','Help with the features settings');

The three arguments are:

package: The package that help is provided for
context: The context within the package that the help is for
description: A discription of what type of help the link is for.

The system will use these paramaters to setup a Smarty variable called TikiHelpInfo with and associative array with the following members:

URL: The url where the help page can be found
Desc: The text of the description of the help that the link is for.