If you have not already figured things out here is some sample code. Basically, all access to the contents of the document is through the Range object. A Range can be the entire document, a paragraph or a single word.
Use the Object Browse (F2) to view all Objects, Methods and Properties that are available within the Word Library.
VB Code:
Dim objWord As Word.Application
Dim objDoc As Word.Document
Set objWord = CreateObject("word.application")
objWord.Visible = True
'Creates a new document
Set objDoc = objWord.Documents.Add
objDoc.Range.Text = "This is a test"
objDoc.Range.Font.Bold = True
objDoc.Range.Font.Italic = True
Set objDoc = Nothing
Set objWord = Nothing