Scott's article style is informative and inspiring. Here is an article about ASP.NET 2.0 Master page tricks and tips. Enjoy :)
In this article, Scott makes the masterpage process clear: Master page replaces the content page's children to itself, then the master page looks for Content control in the controls formerly associated with the content page. When the master page finds a Content control that matches its ContentPlaceHolder, it moves the controls inside the Content control into the matching ContentPlaceHolder. This process happens after the content page's PreInit event, but before the content page's Init event.
Note: At this time, the Content control itself does not exist in content page's DOM tree any more, which means you cannot use ContentControl.FindControl("ctl") .
In the article, Scott gives good suggestion for interaction between mater page and content page. Basic idea is not to bundle mater page and content page too tightly. It is better to use a separate event, and let the two pages subscribe to the event.
There are also several other useful tips. I believe I will refer to that article later.