Here's an example of how to create and customize a chart manually. If you aren't using VS2010 you may need to add some underscores here and there as line continuations.

Imports Infragistics.Windows.Chart
 
Class MainWindow
    Public Sub New()
        InitializeComponent()
 
        Dim chart As New XamChart
        Dim series As New Series With {
            .ChartType = ChartType.Line,
            .Label = "Sample"}
        series.DataPoints.Add(
            New DataPoint() With {.Label = "A", .Value = 1})
        series.DataPoints.Add(
            New DataPoint() With {.Label = "B", .Value = 2})
        series.DataPoints.Add(
            New DataPoint() With {.Label = "C", .Value = 3})
        series.DataPoints.Add(
            New DataPoint() With {.Label = "D", .Value = 4})
 
        chart.Series.Add(series)
 
        Dim yAxis As New Axis With {
            .AxisType = AxisType.PrimaryY,
            .StrokeThickness = 2,
            .Stroke = New SolidColorBrush(Colors.Red)}
 
        chart.Axes.Add(yAxis)
 
        grid.Children.Add(chart)
    End Sub
End Class

Hope this helps!

-Graham