How to create sequential workflow in SharePoint 2010 using Visual Studio 2010

using System;
using System.ComponentModel;
using System.ComponentModel.Design;
using System.Collections;
using System.Drawing;
using System.Linq;
using System.Workflow.ComponentModel.Compiler;
using System.Workflow.ComponentModel.Serialization;
using System.Workflow.ComponentModel;
using System.Workflow.ComponentModel.Design;
using System.Workflow.Runtime;
using System.Workflow.Activities;
using System.Workflow.Activities.Rules;
using Microsoft.SharePoint;
using Microsoft.SharePoint.Workflow;
using Microsoft.SharePoint.WorkflowActions;

namespace SequentialWorkflow.Workflow1
{
    public sealed partial class Workflow1 : SequentialWorkflowActivity
    {
        public Workflow1()
        {
            InitializeComponent();
        }

        public Guid workflowId = default(System.Guid);
        public SPWorkflowActivationProperties workflowProperties = new SPWorkflowActivationProperties();

        private void onWorkflowActivated1_Invoked(object sender, ExternalDataEventArgs e)
        {

        }
    }
}