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.
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