Save and Load plus a few other stuff

I am having a little trouble with some stuff at Unity. First of all, what is the best way to save and load a PC Plataform game?

If it's XML, can someone show me a good and simple example? Because the one I made I got nullreferences at them. If needed, I'll post the code down.

Next issue: When loaded, how to set those values to the right places? Put them through the Start from the codes? Isn't there an easier way? Like a Data Bind, or something?

I am getting null in these:

  `currentHealth = InfoHolder.Instance.CurrentHP;`

And on the SaveData below, that is the InfoHolder.

 > using UnityEngine; using
 > System.Collections;
 > 
 > public class InfoHolder :
 > MonoBehaviour {
 >     public static InfoHolder Instance;
 > 
 >     //Preencher com os mesmos valores que
 > vão ser usados no SaveData. Quando o
 > jogo for carregado, serão passados
 > para cá os valores e vice-versa quando
 > salvo.
 >     //Procure e preencha daqui os valores.
 > 
 >     public int CurrentHP = 100;
 >     public int MaxHP = 100;
 >     public int CurrentMP = 100;
 >     public int MaxMP = 100;
 >     public int Fruits = 0;
 >     public bool LevelChocLabEnter = false;
 > 
 >     public void Bezier()
 >     {
 >         switch (Application.loadedLevel)
 >         {
 >             case 1:
 >                 LevelChocLabEnter = true;
 >                 break;
 >         }
 >     }
 > 
 >     public void CallSave()
 >     {
 >         SaveData.Instance.CurrentHP = CurrentHP;
 >         SaveData.Instance.MaxHP = MaxHP;
 >         SaveData.Instance.CurrentMP = CurrentMP;
 >         SaveData.Instance.MaxMP = MaxMP;
 >         SaveData.Instance.Fruits = Fruits;
 >         SaveData.Instance.levelReached = Application.loadedLevel; //Essa variável pega o último level em que o
 > personagem pisou.
 >         SaveData.Instance.LevelChocLabEnter =
 > LevelChocLabEnter;
 > 
 >         SaveLoad.Save();
 >     } }

Thanks in advance, Pedro Loures.