You don't give much information for exactly where the problems lie. 5 years old combined with kindergarten is a big transitional year for a lot of kids. They aren't toddlers anymore but still lack impulse control and filter.
"SOS for Parents" by Lynn Clark is a book that goes through the time out process that can really work if it is used consistently. I also am a big believer in natural consequences. If a child is screaming/yelling . . . you can tell him very calmly that you will not listen to him until he is using a calm voice. If they throw a toy, they lose the toy. Follow through on anything you say but give a warning first. It takes some time to change habits and behavior so don't think that things will change over night. Stay with a consistent plan even when you don't think it is working. After a month, look for changes in behavior.
Also, 5 year old kids usually really want to please. Praise him like crazy for anything (even things he SHOULD do) he does right like crazy. A reward system can also have a positive effect. One thing you can do is put a bean in a jar every time he does what you ask or a job and when he gets to a certain number of beans (say 20)------ he gets to do an outing with you of his choice.
Also, make sure he has a lot of physical activity in his day. This is directly linked to behavior. Good luck
The child behavior help forum has lots of post similar to yours with lots of good suggestions. Take the time to scroll down through a couple of pages. You will find many helpful ideas that work.
5 yr old...!
get the picture?
try to hard on using words like "DISCIPLINE" and "misbehaving" your gonna find yourself in trouble in a decade or so...
take it easy, have some fun together,
i'm guessing the kids hyperactive, so try to understand that life might get a bit difficult do to that,for the KID! so think a bit about him\her as-well. almost every society has a defect in knowing how to interact with hyperactive kids, so plz, don't make it worse for him\her.
there are allot of different theories about the origin of ADD \ADHD, it's not an illness, and to use a term such as "add\adhd sufferers" usually has to do with frail understanding of surrounding contact (such as school family,etc,etc...