Client Object Model Sample

Get All List Items :

ClientContext clientContext = new ClientContext("http://intranet.contoso.com");
 List list = clientContext.Web.Lists.GetByTitle("Announcements");
 CamlQuery camlQuery = new CamlQuery();
 camlQuery.ViewXml = "<View/>";
 ListItemCollection listItems = list.GetItems(camlQuery);
 clientContext.Load(list);clientContext.Load(listItems);
 clientContext.ExecuteQuery();
 foreach (ListItem listItem in listItems)
 Console.WriteLine("Id: {0} Title: {1}", listItem.Id, oListItem["Title"]);

Creating List using COM, Add Fields and populate Data:

ClientContext clientContext =
            new ClientContext("http://intranet.contoso.com");
        Web site = clientContext.Web;

        // Create a list.
        ListCreationInformation listCreationInfo =
            new ListCreationInformation();
        listCreationInfo.Title = "Client API Test List";
        listCreationInfo.TemplateType = (int)ListTemplateType.GenericList;
        List list = site.Lists.Add(listCreationInfo);

        // Add fields to the list.
        Field field1 = list.Fields.AddFieldAsXml(
            @"<Field Type='Choice'
                     DisplayName='Category'
                     Format='Dropdown'>
                <Default>Specification</Default>
                <CHOICES>
                  <CHOICE>Specification</CHOICE>
                  <CHOICE>Development</CHOICE>
                  <CHOICE>Test</CHOICE>
                  <CHOICE>Documentation</CHOICE>
                </CHOICES>
              </Field>",
            true, AddFieldOptions.DefaultValue);
        Field field2 = list.Fields.AddFieldAsXml(
            @"<Field Type='Number'
                     DisplayName='Estimate'/>",
            true, AddFieldOptions.DefaultValue);

        // Add some data.
        ListItemCreationInformation itemCreateInfo =
            new ListItemCreationInformation();
        ListItem listItem = list.AddItem(itemCreateInfo);
        listItem["Title"] = "Write specs for user interface.";
        listItem["Category"] = "Specification";
        listItem["Estimate"] = "20";
        listItem.Update();

        listItem = list.AddItem(itemCreateInfo);
        listItem["Title"] = "Develop proof-of-concept.";
        listItem["Category"] = "Development";
        listItem["Estimate"] = "42";
        listItem.Update();
        
        listItem = list.AddItem(itemCreateInfo);
        listItem["Title"] = "Write test plan for user interface.";
        listItem["Category"] = "Test";
        listItem["Estimate"] = "16";
        listItem.Update();

        listItem = list.AddItem(itemCreateInfo);
        listItem["Title"] = "Validate SharePoint interaction.";
        listItem["Category"] = "Test";
        listItem["Estimate"] = "18";
        listItem.Update();

        listItem = list.AddItem(itemCreateInfo);
        listItem["Title"] = "Develop user interface.";
        listItem["Category"] = "Development";
        listItem["Estimate"] = "18";
        listItem.Update();

        clientContext.ExecuteQuery();
http://www.codeproject.com/KB/sharepoint/SP2010ClientObjectModel.aspx