tutorial for best-practice hide-and-show UI elements?

[Foj]

Hi, does anyone know of a really good (artist + limited C#) explanation of hiding and un-hiding NGUI UI elements?

I am using - probably very inefficiently - NGUITools.SetActive(true/false). It has taken me half a day to understand that I need to leave a GameObject higher up the hierarchy 'active' to be able set 'false' items back to 'true' - this is the level I am working at 

Any help with writing better code will be much appreciated. Thank you.

1. public class display : MonoBehaviour {
2.  
3.         public static GameObject selectNpc01Message;
4.  
5.         void Start(){
6.         }
7.                
8.         void Update() {
9.                 if (GetComponent<triggerNpc01>().triggerActiveNpc01 == true){
10.                         selectNpc01Message = GameObject.Find("selectNpc01");
11.                         NGUITools.SetActive(selectNpc01Message,true);
12.                         if (Input.GetKeyDown("space")){
13.                         Debug.Log("space key was pressed");
14.                 }
15.                 }
16.                 else{
17.                         selectNpc01Message = GameObject.Find("selectMessage");
18.                         NGUITools.SetActive(selectNpc01Message,false);
19.                         }
20.                 }
21. }