private Web oWebSite = null;
private List oList = null;
private ListItemCollection oListItems = null;
private ClientContext clientContext = null;

this.clientContext = ClientContext.Current;
if (this.clientContext == null)
{
this.clientContext = new ClientContext(url);
}
using (this.clientContext)
{
this.oWebSite = clientContext.Web;
this.oList = this.oWebSite.Lists.GetByTitle(this.listName);
this.oListItems = this.oList.GetItems(CamlQuery.CreateAllItemsQuery());
    clientContext.Load(this.oListItems);
clientContext.ExecuteQueryAsync(onQuerySucceeded, onQueryFailed);
}

private void onQuerySucceeded(object sender, ClientRequestSucceededEventArgs args)
{
//FillItems method converts the List items to Class Properties
//and binds them to the Silverlight User Interface.
this.Dispatcher.BeginInvoke(new Action(FillItems));
}

private void onQueryFailed(object sender, ClientRequestFailedEventArgs args)
{
MessageBox.Show("An error occured.\n" + args.Message + "\n" + args.StackTrace);
}

And if you don’t want all the columns or you want to specify the columns you want to access you can use Caml Query object’s ViewXml property.

CamlQuery camlQuery = new CamlQuery();
string query = "<OrderBy><FieldRef Name='Name' Ascending='False' /></OrderBy>";
camlQuery.ViewXml = query;
this.oListItems = this.oList.GetItems(camlQuery);

You can access CustomLists and Document Libraries by this method.

Here is my first experiment with Silverlight Object Model which helps to retrieve all the Lists from a given SharePoint site, and displays it in a Combo Box.

private Web oWebSite;
private ListCollection collList;
private void UserControl_Loaded(object sender, RoutedEventArgs e)
{
    using (ClientContext clientContext = new ClientContext("http://sharepoint2010/"))
    {
        this.oWebSite = clientContext.Web;
        this.collList = this.oWebSite.Lists;
        clientContext.Load(collList);
        clientContext.ExecuteQueryAsync(onQuerySucceeded, onQueryFailed);
    }
}

private void onQuerySucceeded(object sender, ClientRequestSucceededEventArgs args)
{
    this.Dispatcher.BeginInvoke(new Action(DisplayLists));
}
private void onQueryFailed(object sender, ClientRequestFailedEventArgs args)
{
    MessageBox.Show("An error occured.\n" + args.Message + "\n" + args.StackTrace);
}

private void DisplayLists()
{
    foreach (List item in collList)
    {
        lstItems.Items.Add(item.Title);
    }
}

Because query execution is asynchronous when you use the SharePoint Foundation Silverlight object model, you must pass delegates for callback methods as parameters in the ExecuteQueryAsync(ClientRequestSucceededEventHandler, ClientRequestFailedEventHandler) method.

SPUtility.SendEmail(SPContext.Current.Site.OpenWeb(), false, false, "admin@myserver.com", "Hello World", "This is a Sample Mail");

This will send a mail to “admin@myserver.com”, with “Hello World” as subject and “This is a Sample Mail” as body. You can send HTML emails by changing the third parameter to TRUE.

Update : You may need to use SPSecurity.RunWithElevatedPrivileges method to send mails.

Url :

http://msdn2.microsoft.com/en-us/library/microsoft.sharepoint.spsecurity.runwithelevatedprivileges.aspx

This method enable users to Execute the specified method with Full Control rights even if the user does not otherwise have Full Control.