Ideal setting vary a little bit, but a good start is to use a strategic approach. THe best settings allow you to stop motion, and to shoot FAST, without the need for steadying-down and slow-fire breathing techniques. That means a moderate f/stop, like say f/5.6, and a fast-ish shutter speed, like 1/300 second to 1/500 second.
Setting that exposure, f/5.6 at 1/300 or 1/350 second is great with any shorter lens, like an 18-55 mm zoom. With a modern d-slr, using Manual mode and AUTO-ISO with the maximum ISO value set to 1,600, you'll be good to go from 2 hrs after sunrise to 2 hours before sunset with a shorter lens.
A longer lens, like an 80-200 or 70-300 also needs f/5.6 or so, but a bit faster speed of 1/500 to 1/800 second is best in daylight hours.
If you really,really have NO time to waste, the correct AUTO ISO set-up will be of huge value.
Get LOW. Watch the backgrounds very,very carefully. Candid kid photography is very demanding--you must constantly keep one eye on the child, and one eye on the background, as seen through the viewfinder. I'm not kidding--this kind of photography demands that you make a LOT of very fast decisions, moving over to the left, over to the right is a constantly- occurring thing you need to do to keep the backgrounds under control. The wider the lens angle, the more background you get, which can be helpful at times, to show context and location, or it can just as easily, allow in cluttery stuff. Look for clean backgrounds.
Have you ever thrown a fistful of pocket change into a lawn and seen what happens? Especially one that has plenty of dimes and quarters in it.