Make sure you've got them active throughout the day; take them to the park to run around or play games in the backyard, etc. Don't feed them lots of sugar throughout the day, and especially not once the sun's down. Turn off the tv a few hours before you want them to sleep. And then before bed, read them a story or sing them some songs in dim light. After that, tell them it's time for bed, and turn out the light and leave. If they keep getting out of bed, just continue to put them back into it for however long it takes for them to stay, and eventually they'll get the picture.
Sometimes kids can be hectic dealing with them. However, you can plan in a manner that the kid has dinner served early enough and then she sleeps early. This should be the daily routine so that the child adapts to it.
You could try playing a game that will let out some energy before he or she goes to bed. It could even teach him or her how to do or learn more about something (reading, sports, music, or anything he or she likes). They may be to young to do a lot, but it is also a good way to spend time together.
Don't give in, don't let him win, let him cry for 10 minutes then go in one time and say ok bed now, pat him, say you are ok, now sleep. then leave again. When he sees you will not cave in he will give up. It takes consistency and endurance on your part for about three nights.