how can my object able to glow on mouse over. what are the things i need to do. please help.
For GUI objects, see this answer:
http://answers.unity3d.com/questions/8217/mouseover-detection
For 3D objects see this answer:
http://answers.unity3d.com/questions/35784/change-mouse-cursor-on-mouseover
http://answers.unity3d.com/questions/10591/text-box-pop-up-on-mouseover
It basically comes down to this script:
http://unity3d.com/support/documentation/ScriptReference/MonoBehaviour.OnMouseEnter.html
If you are not familiar with how to use the scripting side of Unity, I'd recommend running through a bunch of tutorials to buff up your knowledge first.