<configuration>
  <configSections>
    <section name="enterpriselibrary.configurationSettings"
        type="Microsoft.Practices.EnterpriseLibrary.Configuration.
        ConfigurationManagerSectionHandler,
        Microsoft.Practices.EnterpriseLibrary.Configuration, Version=1.0.0.0,
        Culture=neutral,
        PublicKeyToken=null" />
  </configSections>
  <enterpriselibrary.configurationSettings
        xmlns:xsd="http://www.w3.org/2001/XMLSchema"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        applicationName="configtest"
        xmlns="http://www.microsoft.com/practices/enterpriselibrary/08-31-2004/configuration">
  <configurationSections>
    <configurationSection name="SiteSettings" encrypt="false">
      <storageProvider xsi:type="XmlFileStorageProviderData"
           name="XML File Storage Provider"
           path="sitesettings.config" />
      <dataTransformer xsi:type="XmlSerializerTransformerData"
           name="Xml Serializer Transformer">
        <includeTypes />
      </dataTransformer>
    </configurationSection>
  </configurationSections>
  <keyAlgorithmStorageProvider xsi:nil="true" />
  <includeTypes />
</enterpriselibrary.configurationSettings>
</configuration>

using System;
using Microsoft.Practices.EnterpriseLibrary.Configuration;

public class SiteSettings
{
    #region Private Members
    
    private string _name;
    private string _url;
    private string _emailAddress;
    
    #endregion
    
    #region Properties

    public string Name
    {
        get { return _name; }
        set { _name = value; }
    }
    
    public string Url
    {
        get { return _url; }
        set { _url = value; }
    }
    
    public string EmailAddress
    {
        get { return _emailAddress; }
        set { _emailAddress = value; }
    }
    
    #endregion
}

public class TestClass
{
    public static void Main()
    {
        SiteSettings siteSettings = new SiteSettings();

        siteSettings.Name = "DavidHayden.com";
        siteSettings.Url = "http://www.davidhayden.com/";
        siteSettings.EmailAddress = "nospam@nospam.com";
        
        ConfigurationManager.WriteConfiguration("SiteSettings", siteSettings);
        
        SiteSettings mySettings = ConfigurationManager.GetConfiguration("SiteSettings") as SiteSettings;
        
        if (mySettings != null)
        {
            Console.WriteLine("Name = {0}", mySettings.Name);
            Console.WriteLine("Url = {0}", mySettings.Url);
            Console.WriteLine("Email Address = {0}", mySettings.EmailAddress);
            Console.ReadLine();
        }
    }
}

<?xml version="1.0" encoding="utf-8"?>
<SiteSettings>
  <xmlSerializerSection type="SiteSettings, configtest,
            Version=0.0.0.0, Culture=neutral, PublicKeyToken=null">
    <SiteSettings xmlns:xsd="http://www.w3.org/2001/XMLSchema"
            xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
      <Name>DavidHayden.com</Name>
      <Url>http://www.davidhayden.com/</Url>
      <EmailAddress>nospam@nospam.com</EmailAddress>
    </SiteSettings>
  </xmlSerializerSection>
</SiteSettings>