All,

My Excel VBA programming is decent enough when I stay within Excel.
However, I'm trying to expand my knowledge base and frequently I wish
I could better interact with other Office programs, such as Outlook.
Here's a piece of code that works great but I don't fully understand.

Private Sub UserForm_Activate()

Dim x As Integer

Set objOL = CreateObject("Outlook.Application")
Set olNS = objOL.GetNamespace("MAPI")
Set myFolder = olNS.GetDefaultFolder(10)
Set myItems = myFolder.Items

myItems.Sort "FullName"

x = 0
For Each myContact In myItems
If TypeName(myContact) = "ContactItem" Then
If Len(myContact.Email1DisplayName) 0 Then
ListBox1.AddItem
ListBox1.Column(0, x) = myContact.Email1DisplayName
ListBox1.Column(1, x) = myContact.Email1Address
x = x + 1
End If
End If
Next myContact

Set olNS = Nothing
Set objOL = Nothing

End Sub

My basic question is this: Can anyone suggest a good reference to
learn the uses and codes associated with objects, variables,
constants, etc..., which relate to programs outside Excel? For
example, in the above code I do not understand the precise usage of
GetNamespace("MAPI"), GetDefaultFolder(10), myFolder.Items,
Email1DisplayName, Email1Address, etc..., etc...

I don't like using code I don't understand for many obvious reasons.
Clearly, Email1DisplayName is a particular field in the OL Address
Book, but how do I learn what all of these fields are called? Where do
I obtain syntax info for Outlook Object references? Etc.., Etc....I
think you'll all get what I'm asking.

Thanks, everyone!