http://www.parents.com/baby/sleep/basics/age-by-age-guide/

Newborns sleep in 2- to 4-hour intervals, waking up to eat.
Babies this age tend to stir and look restless during sleep. Because of reflexes they can't control, it's common to see them twitch their arms and legs, smile and make sucking noises.
Newborns aren't born knowing how to soothe themselves to sleep, so you may need to help, with tricks like using a pacifier, swaddling, rocking and breastfeeding. Remember, there's no such thing as spoiling a newborn, so it's OK to cuddle baby to help her doze off.

Babies this age may sleep for six-hour stretches at night, and settle into more of a set nap schedule now.
To get baby on a good sleep routine, make sure to play and expose her to lots of sunlight during the day and avoid over-stimulating her when it's dark out.
Starting a pre-bedtime sleep routine -- like bath, feeding, story time -- can help ready baby to sleep through the night for longer stretches.

Babies this age will start to quit nighttime feedings, and are usually ready to sleep through the night now, anywhere from six- to 12-hour stretches.
Research shows about 60 percent of babies sleep through by 6 months, up to 80 percent do so by 9 months.
Remember, all babies wake up sometimes during the night, but those who "sleep through" have learned how to nod off on their own.

Some babies stop sleeping through the night now because of separation anxiety. Your baby knows you're around even when she can't see you, and may get upset when she wakes up.
It's OK to go in and check on your crying baby, but keep visits short and try (as hard as it is) not to pick her up or feed her. Try rubbing her back, singing a soothing lullaby and ducking out after a few minutes.

Active toddlers can have trouble relaxing and winding down at night -- causing bedtime battles. Try to keep things as calm as possible in the evenings, sticking to soothing activities like bath and story time.
Once baby learns to climb out of the crib, she may attempt to snuggle in bed with you. This is a hard-to-break habit, so if you don't want to start a co-sleeping situation, bring her back to her own room.

Toddler and preschooler sleep problems include procrastinating and resisting bedtime, getting out of their big-kid beds when they wake at night, and developing night fears.
Stick to a bedtime routine and sleep schedule, make sure your kids understand the rules and be consistent about enforcing them.
Using a nightlight or lovey can comfort kids who tend to get scared of the dark or have nightmares.

Homework, a jam-packed social schedule and computer and TV time tend to push back bedtime.
Cutting back on soda or other caffeine-packed drinks, as well as reducing TV-watching right before bed can help.
Children with sleep-friendly bedrooms -- dark, cool and quiet, with no TV or computer -- tend to sleep better than those with lots of distractions.

Babe Camelia