To fill a dataset from a stored procedure you would have code like below:
SqlConnection mySqlConnection =new SqlConnection("server=(local);database=MyDatabase;Integrated Security=SSPI;");
SqlCommand mySqlCommand = mySqlConnection.CreateCommand();
mySqlCommand.CommandText = "IDCategory";
mySqlCommand.CommandType = CommandType.StoredProcedure;
mySqlCommand.Parameters.Add("@IDCategory", SqlDbType.Int).Value = 5;
SqlDataAdapter mySqlDataAdapter = new SqlDataAdapter();
mySqlDataAdapter.SelectCommand = mySqlCommand;
DataSet myDataSet = new DataSet();
mySqlConnection.Open();
mySqlDataAdapter.Fill(myDataSet);
Your connection string will be different and there are a few different ways to do this but this should get you going.... Once you get a few of these under your belt take a look at the Using Statement. It helps clean up the resources and requires a few less lines of code. This assumes a Stored Procedure name IDCategory with one Parameter called the same. It may be a little different in your setup.
Your stored procedure in this case will look something like:
CREATE PROC [dbo].[IDCategory]
@IDCategory int
AS
SELECT IDListing, IDCategory, Price, Seller, Image
FROM whateveryourtableisnamed
WHERE IDCategory = @IDCategory
Here's a link on Stored Procedure basics:
http://www.sql-server-performance.com/articles/dba/stored%5Fprocedures%5Fbasics%5Fp1.aspx
Here's a link on DataSets and other items with ADO.Net:
http://authors.aspalliance.com/quickstart/howto/doc/adoplus/adoplusoverview.aspx