Ok, so I found that for some reason I thought I did a post on this before and I couldn't find it. So I thought I would make a new post as simple as possible. Here is a simple dp:

public readonly DependencyProperty ResistanceProperty = DependencyProperty.Register("Resistance", typeof(double), typeof(AnimatingPanelBase), null);
public double Resistance
{
get
{
return (double)GetValue(ResistanceProperty);
}
set
{
SetValue(ResistanceProperty, value);
}
}

Nice and simple right? why bother you ask, well the biggest issue is that if you want to animate properties of a custom control of some kind using data binding and what that change to filter into the UI of some control. Otherwise I try to avoid DP's as much as possible. So if you need todo some mucking around in your control after the DP value has changed then do this:

public static readonly DependencyProperty MinimumProperty = DependencyProperty.Register("Minimum", typeof(double), typeof(Dial), new PropertyMetadata(new PropertyChangedCallback(OnMinimumChanged)));

public double Minimum
{
get
{
return (double)GetValue(MinimumProperty);
}
set
{
SetValue(MinimumProperty, value);
}
}
private static void OnMinimumChanged(DependencyObject DpObj, DependencyPropertyChangedEventArgs e)
{
// some code :
}

You'll note that this has a changed handler but otherwise is like the first version. and that is pretty much it. :)