How to Create Timer Job for Beginers

//First Create Empty project in sharepoint
//after that create one cs file in this project
//write following code in CS file

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Microsoft.SharePoint;
using Microsoft.SharePoint.Administration;


namespace timerjobApplication
{
    class CustomTimerJob:SPJobDefinition
    {
        public CustomTimerJob() : base() { }

        public CustomTimerJob(string jobName, SPService service) :
            base(jobName, service, null, SPJobLockType.None)
        {
            this.Title = "Task Complete Timer";
        }

        public CustomTimerJob(string jobName, SPWebApplication webapp) :
            base(jobName, webapp, null, SPJobLockType.ContentDatabase)
        {
            this.Title = "Task Complete Timer";
        }
        public override void Execute(Guid targetInstanceId)
        {
            SPWebApplication webApp = this.Parent as SPWebApplication;
            SPList taskList = webApp.Sites[0].RootWeb.Lists["Tasks"];
            SPListItem newTask = taskList.Items.Add();
            newTask["Title"] = "New Task" + DateTime.Now.ToString();
            newTask.Update();
        }
    }
}


//After that go to feature file of this solution
// in feature file call the function for timer job in feature Activated method

CreateJob(parentWebApp);



//After that write below  function for timer job in same feature file

private bool CreateJob(SPWebApplication site)
       {
           bool jobCreated = false;
           try
           {
               CustomTimerJob job = new CustomTimerJob(JobName, site);
               SPMinuteSchedule schedule = new SPMinuteSchedule();
               schedule.BeginSecond = 0;
               schedule.EndSecond = 59;
               schedule.Interval = 3;
               job.Schedule = schedule;

               job.Update();
           }
           catch (Exception)
           {
               return jobCreated;
           }
           return jobCreated;
       }

//After that deploy this and check the timer function working in list 'Task'