Add note on data visibility delay in Azure Monitor

Added a note about data appearance time in Azure Monitor.

Author: staleycyn

Instructions/Labs/LAB_11-Implement_Monitoring.md

@@ -207,6 +207,8 @@ Enter these settings for the scheduling of the alert processing rule:
 
 In this task, you will use Azure Monitor to query the data captured from the virtual machine.
 
+    >**Note:** It can take 15-30 minutes for data to appear. Concentrate on the method and types of queries, rather than the results. 
+
 1. In the Azure portal, search for and select `Monitor`, then click **Logs**.
 
 1. If necessary, close the splash screen.