C# - LinkedList Class

using System;

namespace ConsoleApplication2
{
    public class LinkedList
    {
        private class Node
        {
            public object Data;
            public Node Next;
        }

        // Set first and last Node
        private Node first;
        private Node last;

        //Count Nodes
        public int Count { get; private set; }

        //Add´s a new Node
        public void Add(object data)
        {
            Node newNode = new Node() { Data = data };

            if (first == null)
            {
                first = newNode;
                last = newNode;
            }
            else
            {                
                last.Next = newNode;
                last = newNode;
            }
            
            Count++;
        }
    }
}