Sharepoint Programming using Lists.asmx,dws.asmx and webs.asmx

Sample Code to work with Lists.asmx and also we can work with Dws.asmx and webs.asmx

/*Declare and initialize a variable for the Lists Web service.*/Web_Reference.Lists listService = new Web_Reference.Lists();
/*Authenticate the current user by passing their default credentials to the Web service from the system credential cache.*/
listService.Credentials = System.Net.CredentialCache.DefaultCredentials;
/*Set the Url property of the service for the path to a subsite.*/
listService.Url = "http://Server_Name/Subsite_Name/_vti_bin/Lists.asmx";
// Instantiate an XmlDocument
objectSystem.Xml.XmlDocument xmlDoc = new System.Xml.XmlDocument();
/* Assign values to the string parameters of the GetListItems method, using GUIDs for the listName and viewName variables. For listName, using the list display name will also work, but using the list GUID is recommended. For viewName, only the view GUID can be used. Using an empty string for viewName causes the default view to be used.*/
string listName = "{17991794-81BB-494F-9910-CFBF1093A7CF}";
string viewName = "{7137FFF8-48FF-4C69-8C76-0E3BBD1EA7F9}";
string rowLimit = "150";
/*Use the CreateElement method of the document object to create elements for the parameters that use XML.*/
System.Xml.XmlElement query = xmlDoc.CreateElement("Query");
System.Xml.XmlElement viewFields = xmlDoc.CreateElement("ViewFields");
System.Xml.XmlElement queryOptions = xmlDoc.CreateElement("QueryOptions");
/*To specify values for the parameter elements (optional), assign CAML fragments to the InnerXml property of each element.*/query.InnerXml = "" + "3";viewFields.InnerXml = "";queryOptions.InnerXml = "";
/* Declare an XmlNode object and initialize it with the XML response from the GetListItems method. The last parameter specifies the GUID of the Web site containing the list. Setting it to null causes the Web site specified by the Url property to be used.*/
System.Xml.XmlNode nodeListItems =listService.GetListItems (listName, viewName,query,viewFields,rowLimit,queryOptions,null);
/*Loop through each node in the XML response and display each item.*/
foreach (System.Xml.XmlNode listItem in nodeListItems)
{
label1.Text += listItem.OuterXml;
}

Please go through the Urls

http://msdn.microsoft.com/en-us/library/cc768559.aspx
http://msdn.microsoft.com/en-us/library/ms429658.aspx
http://msdn.microsoft.com/en-us/library/lists.aspx
http://msdn.microsoft.com/en-us/library/ms774834.aspx
http://msdn.microsoft.com/en-us/library/webs.aspx