This console application allows you to start, stop, list and query running tasks. The DoStuff() method does the work itself - 50 iterations of sleeping for 10 seconds.

TplExample.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Security.Permissions;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace TplTest
{
	class Program
	{
		private static List<Task<MyRunner>> tasks = new List<Task<MyRunner>>();

		static void Main(string[] args)
		{
			Console.WriteLine("Commands: start, list, stop, start {amount}, stop {taskid}, c to quit.");
			string input = Console.ReadLine();
			while (input != "c")
			{
				if (input.StartsWith("start"))
				{
					HandleStartCommand(input);
				}

				if (input == "list")
				{
					HandleListCommand();
				}

				if (input.StartsWith("stop"))
				{
					HandleStopCommand(input);
				}

				input = Console.ReadLine();
			}
		}

		private static void HandleStopCommand(string input)
		{
			int taskId = 0;
			string number = input.Replace("stop", "");
			if (!int.TryParse(number, out taskId))
				taskId = 0;

			if (taskId > 0)
			{
				Task<MyRunner> task = tasks.FirstOrDefault(t => t.Id == taskId);
				if (task != null)
				{
					task.Result.CancelTokenSource.Cancel(false);
					Console.WriteLine("Attempting to stop task id {0}", taskId);
				}
			}
			else
			{
				Console.WriteLine("Can't parse {0} as a task id", number);
			}
		}

		private static void HandleListCommand()
		{
			foreach (Task<MyRunner> task in tasks)
			{
				Console.WriteLine("{0} {1} {2}", task.Id, task.Result.ChildTask.Status, task.Result.Show());
			}
		}

		private static void HandleStartCommand(string input)
		{
			int repeat = 1;
			string count = input.Replace("start", "");
			if (!int.TryParse(count, out repeat))
				repeat = 1;

			for (int i = 0; i < repeat; i++)
			{
				CancellationTokenSource cancelSource = new CancellationTokenSource();
				CancellationToken cancelToken = cancelSource.Token;

				MyRunner runner = new MyRunner(Guid.NewGuid(), cancelSource);
				Task<MyRunner> parentTask = Task.Run(() =>
				{
					Task childTask = Task.Run(() => { runner.DoStuff(); }, cancelToken);

					runner.CancelTokenSource = cancelSource;
					runner.ChildTask = childTask;
					return runner;
				});

				tasks.Add(parentTask);
			}
		}
	}

	public class MyRunner
	{
		public Task ChildTask { get; set; }
		private readonly Guid _id;
		public CancellationTokenSource CancelTokenSource { get; set; }
		private int _step;

		public MyRunner(Guid id, CancellationTokenSource cancelToken)
		{
			_id = id;
			CancelTokenSource = cancelToken;
		}

		public void DoStuff()
		{
			Console.WriteLine("Running {0}", _id);

			for (int i = 0; i < 50; i++)
			{
				if (CancelTokenSource.IsCancellationRequested)
					break;

				Thread.Sleep(10000);
				_step++;	
			}
		}

		public string Show()
		{
			string cancelMessage = "";
			if (CancelTokenSource.Token.IsCancellationRequested)
			{
				cancelMessage = "(cancelled)";
			}

			return string.Format("{0} - I'm at, or got to step {1} {2}", _id, _step, cancelMessage);
		}
	}
}