Coaching Youth Basketball

Teach fundamentals of the dribbling and passing and shooting, but make sure they are using balls that are the size for them.  Also, involve the parents if at all possible.  Have the parents pass the ball back and forth with their child.  Have them do sprints to a corner one at a time and then wait for the next child to get there then they sprint to the next marked corner.  Have them shoot at lowered or portable hoops, so they are not throwing the ball buy actually learning to shoot the ball.  Get on your knees and play basketball with each of them.  On your knees be in front of them and make them shoot over you.  Encourage them.  They should be having fun.  Do some type of warm up exercises, and do 10 of each and let each child pick what they want to do and do them with them and get their parents to do them also.  Involve everyone you can.  Make it fun.

Dribble.  Explain double dribble.  Explain travel.  Pass.  Bounce pass.  Layups, right side, left side.  Hands up on defense.  What a foul is.  What a steal is.  Tying up the ball for a jump.  Block out and rebound.  How to shoot it back up fast when you get a rebound.  How to inbound.  Maybe teach the stack.  Some of these concepts are probably more than many 6 and under will grasp.  But it's a learning curve.  Repetition is good.  Invariably you will go up against some team(s) with what appears to be a 10-year-old with a fake birth certificate.  Don't sweat it.

Keep it positive.  Keep it fun.  Kids like fun.

Some of the posters gave some good generic tips.  I have taught youth basketball and my philosophy is always hit those basics and reinforce those basics, ex. dribbling with right hand, dribbling with left hand, keeping head up and staying low is important, protecting the ball, passing with proper hand positioning and eye contact, etc.

Hopefully the organization will provide the basketballs for you.  The basketball size should be, as per this link:
"The Mini International Size 3 basketball has a circumference between 22 to 22.5 inches. It weighs 10.5-11.25 ounces. It is recommended for younger children ages 5-8.

Attention spans are not long with youths, as you know, so have your 5 - 10 min. drills ready to go with teaching by example and then having the kids practice those skills - ball handling/dribbling, passing.  Remember to have a short break (bathroom and water break) about halfway through.

Keep their attention focused on you and not bouncing the ball, etc.

Don't get that involved with attempting to show plays and such - it won't work, especially at that age.

Incorporate a lot of "games" to allow the skills to happen, for example:
1). Shark and fishes.  The kids start on the end line with a basketball on one side, and the boundary is the sidelines).  The instructor is "it" first.  The kids and the person who is "it" will have a basketball.  The instructor tells the kids as to what hand to dribble with or if they can alternate, and then tell the kids when to go to run to the other end line.  The person who is "it" will have to dribble, too, trying to tag the "fishes" before they race down to the other end line, all the while still dribbling.  If they lose their dribble, then they have to get the ball and start from where they lost the dribble.  No one can step outside the boundaries or they become "it".  The last fish standing wins.  The first fish that was tagged is the new shark.  Does this make sense?
Hopefully, some parents can assist with watching the boundaries and dribbling drops.

2). Depending on how many kids (usually 8 - 10 can do this), all the kids are gathered in the middle of the court in the jump ball area.  The kids have to dribble with either their right hand, or left hand, or either hand (you tell them during that time), and the kids try to knock out/swat another kid's ball away from them while they are all dribbling.  Also, the kids can not step out the circle border (must stay inside the circle, or if there is a 4-square setup you can use that).  A kid is out when one of the following happens:
  a). Ball is knocked away.
  b). Kid steps outside the border.
  c). Kid stops dribbling.  However, it's up to your discretion if double-dribbling is acceptable.
It's always good if a couple of parents can assist since it isn't easy to monitor these games by yourself.

I'm starting up my program with 3rd graders real soon.

Best of luck to you!