Q:

what is the best way to use charts and gauge controls in wpf/c#? 

Are there any good libraries for charts and gauche controls (WPF/.net 4.5/C#)?  I need them to embed into a windows application, which should run under windows embedded.  probably windows embedded 8. 
thanks for your help. 

A:

This tutorial demonstrates how to draw various charts including line chart, bar chart, column chart, area chart, scatter chart, and pie chart using WPF and C#. 
And there is a
Free tools supporting panning / zooming:

DynamicDataDisplay - a nice, open source data visualization
library.  Unfortunately it's not been updated since April 30, 2009. 

Free tools without built in pan / zoom support:

WPF Toolkit.  Supports most important 2D charts, you'll have to
implement pan / zoom yourself. 

And a 
Paid tools with built in pan / zoom support:

Visiblox Charts.  Support for the most important 2D charts, comes with
zooming and panning.  The free version comes with watermark. ( See this
blog post on using zooming / panning)
SciChart.  Supports most important 2D charts, comes with zooming and
panning, mouse-wheel with animation on zoom. ( See this blog post on
using zooming / panning across multiple charts)
Infragistics xamDataChart.  Supports most important 2D charts, zooming
and panning.  See this blog article on how to use zooming. 
Telerik RadChart.  Supports lots of 2D charts, has some support for
zooming and panning, you might need to do a little work on that. 
Visifire.  Supports lots of 2D charts and zooming without animation,
might need to do some extra work for smoother zooming.