Private objControl As Control
Protected Overrides Sub RenderWebPart(ByVal output 
                                     As System.Web.UI.HtmlTextWriter)
    objControl.RenderControl(output)
End Sub
Protected Overrides Sub CreateChildControls()
    objControl = Page.LoadControl("/UserControls/PubsDisplay.ascx")
    Controls.Add(objControl)
End Sub

Example 4: Loading and rendering the Web User Control.