How To Encrypt My Password Or Sensitive Data Before Storing Them In A Database , Using SQL Server 2005?[urgent Plz Help]

Hi there ,
1. i have a database and i want to encrypt my passwords before storing my records in a database plus i will later on would require to  authenticate my user so again i have to encrypt the string provided by him to compare it with my encrypted password in database

below is my code , i dont know how to do it , plz help 
2. one thing more i am storing IP addresses of my users as a "varchar" is there a better method to do it , if yes plz help me

 
   try
        {
            SqlConnection myConnection = new SqlConnection();
            myConnection.ConnectionString = ConfigurationManager.ConnectionStrings["projectConnectionString"].ConnectionString;

            SqlDataAdapter myAdapter = new SqlDataAdapter("SELECT *From User_Info", myConnection);
            SqlCommandBuilder builder = new SqlCommandBuilder(myAdapter);
            DataSet myDataset = new DataSet();
            myAdapter.Fill(myDataset, "User_Info");

            //Adding New Row in User_Info Table   
            DataRow myRow = myDataset.Tables["User_Info"].NewRow();
            myRow["user_name"] = this.user_name.Text;
            myRow["password"] = this.password.Text; // shoule be encrypted
            //not known till now how to do it
          
            myRow["name"] = this.name.Text;
            myRow["ip_address"] = this.ip_address.Text;
            
            myDataset.Tables["User_Info"].Rows.Add(myRow);
            myAdapter.Update(myDataset, "User_Info");

            myConnection.Close();
            myConnection.Dispose();


        }
        catch (Exception ex)
        {
            this.error.Text = "Error ocurred in Creating User : " + ex.Message;
        }