From website About.com, this might be helpful...
The five-year old lives in the here and now, and doesn't comprehend the idea of long-term consequences. He has difficulty seeing a point of view that is different from his own and this can make him seem stubborn and argumentative. But, he is generally cooperative and helpful, wanting to please his parents and be good. He may come home from kindergarten talking about a child who is bad. This is a good time to help him recognize what happens when someone behaves badly and to praise him for his good behavior.
Five has a good imagination and that can manifest as lying. It's best to treat lying with a light touch this year. Let her know that you know she is 'pretending' or not telling the truth. If she lies to avoid punishment, talk to her about the importance of telling the truth and add a small consequence for not doing so.
Because of five's here and now mindset, consequences for misbehavior and non-compliance should be immediate and brief. Don't expect that he'll learn his lesson the first, or even the tenth, time he receives a consequence. He hasn't yet learned self-control; and so, discipline this year involves baby steps, not giant leaps. Don't give up and don't get frustrated; just keep on giving consequences for misbehavior consistently with the attitude that he has the desire to be good, but is still learning
Daily structure and routines are important throughout childhood; but this is a transition year, so structure is crucial to your child's security and well-being. As much as possible, her life should revolve around familiar people, places, and routines.
When behavior problems occur, make sure that your child is getting plenty of rest and regular meals; cut back on outside activities to focus on familiar daily routines; catch him being good and praise him; and give immediate instruction or consequences for misbehavior.
Hope that helps.