The biggest and exhaustive resource - http://helpware.net/FAR/.

For VB.Net (as it is done by me).

1. I add on form HelpProvider and I name it HelpProvider.
   
   
   
2. I define its properties
   
   
   

I add lines of a kind
At loading the form (reaction for key F1)
HelpProvider.HelpNamespace = Application.StartupPath & «\» & AssName & «.chm»
HelpProvider.SetHelpNavigator(Me, HelpNavigator.TableOfContents)

At definition of the menu

Private Sub mnuHelpChm_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles mnuHelpChm.Click
Help.ShowHelp(Me, HelpProvider.HelpNamespace)
End Sub

Private Sub mnuIndexHelp_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles mnuIndexHelp.Click
' Show index of the help file.
Help.ShowHelpIndex(Me, HelpProvider.HelpNamespace)
End Sub

Private Sub mnuSearchHelp_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles mnuSearchHelp.Click
' Show the search tab of the help file.
Help.ShowHelp(Me, HelpProvider.HelpNamespace, HelpNavigator.Find, ««)
End Sub

At initialization of the program for definition of the contextual help

HelpProvider.SetHelpKeyword(txtFileFolder, Strings.TTtxtFileFolder)
HelpProvider.SetHelpNavigator(txtFileFolder, HelpNavigator.KeywordIndex)

3. In class Strings
   Public TTtxtFileFolder As String = « Path for Word file. Drag and drop a file here or use the button.»
4. I use class Strings for definition Controls properties such as Text and ToolTip. It is convenient, as is in one place, can be easily compared to other descriptions, and also enables concerning easy translation into other language.
5. . Example of file Strings is given Appendix 3.
6. My ToolTip defines as 
   ToolTip.SetToolTip(txtFileFolder, Strings.TTtxtFileFolder)

Thus, both for the contextual Help and for ToolTip I use one definition. There is no difference, there are no divergences. To tell more, my block of comments in the text of the program looks the following way

''' -----------------------------------------------------------------------*
''' <summary> Path for Word file. Drag and drop a file here or use the button.</summary>
''' <history>[DPosudin] 7 July 2005. 17:19:00</history>
''' -----------------------------------------------------------------------*
Private Sub txtFileFolder_DragEnter(ByVal sender As Object, ByVal e As System.Windows.Forms.DragEventArgs) Handles txtFileFolder.DragEnter

It means, that I only once in tag <summary> have described a method and this description is used four times - as ToolTip, as an index for the contextual help, in the documentation and in the description of a method.

For Access, and also other languages, see. articles of firm Indigoware Ltd.