Hello Shailesh.Rathod, I think you can practice some tutorials that is available in your software [both tutorial data(C:\ArcGIS\ArcTutor\Network_Analyst folder) and pdf files(C:\Program files\ArcGIS\Doccumentation\Network_Analyst )]. And for more information you can take help from your ArcGIS desktop help in your help menu. For more and more information you can browse esri ( http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#//00470000005r000000 ) and youtube video files. Hope you can overcome your problem. Best of Luck Hayat
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