Senses: Your newborn's eyesight is around 20/400 (perfect vision is 20/20), so things look pretty fuzzy. She can see just 30 inches ahead and prefers to focus on objects that are even nearer, so get up close! She not only recognizes your smell but prefers it above others. And she loves hearing your voice, so talk to her, sing songs, and if you hear her make a sound, join her in a "conversation."
Body: Hands are mostly clenched in little fists, and legs are bunched up like they were in the womb. The grasping reflex makes your baby hold tight to your fingers.
Brain: Your baby was born with a whopping 100 billion neurons (cells that make up the brain and nerves).
Communication Skills: It's all about crying -- three hours a day, give or take, but it can seem like 24-7. The trick is trying to figure out what she needs. Soon enough, you'll be a pro at knowing just how to comfort her.
Aww Factor: "Hey, Sweet Pea!" -- your baby recognizes your voice and may turn her head in your direction.
Fave Toy: Your hair -- so fun to pull, twist, and coil fingers in. (Ponytails are a mom's best friend.)
Playtime: The silly-face game. Your baby is a rapt audience of one -- when she's looking at you intently, open and close your eyes, stick out your tongue, smile. That's entertainment!
Mealtime: For the next four or five months, your infant dines on breast milk or formula exclusively. If you're bottle feeding and concerned about potential tummy issues, like colic, gas or reflux, try using an anti-colic bottle. Philips Avent has one with a unique AirFree vent that keeps the nipple full of milk during feeding, which means your baby swallows less air as they drink.
Body: As his neck control improves, your newborn will be able to keep his head up when you hold him in a sitting position. His hands also start to unfold. And he's packing on as much as half a pound a week.
Brain: During half the hours your baby is asleep, he's in the REM cycle, when dreaming occurs. Scientists believe infants use this time to process the mounds of information they absorb during the day.
Communication Skills: Is there a dove in the house? Nah, it's just your baby, who has started to coo. You're beginning to notice his emerging temperament -- is he a quiet thinker? A feisty little guy?
Aww Factor: His favorite spot for a catnap is curled up on your chest.
Fave Toy: A mobile. He's fascinated by its shapes and movements.
Playtime: Monkey see, monkey do. Imitating your baby's sounds and expressions is a fun way to communicate.
Mealtime: By this point, infants instinctively know how much they need to eat to grow, so as long as your baby seems content, stop stressing about over- or underfeeding him.
Senses: Eye coordination has improved so much that your baby can now easily follow an object through a 180-degree arc. That means playtime is more fun and dynamic -- patty-cake, anyone?
Body: When lying on her stomach, your little one peels her chest off the ground and lifts her head up 45 degrees (in yoga, this is aptly called Baby Cobra).
Brain: Your baby's burgeoning understanding of the world is based on predictable patterns, so when you stray from your normal routine -- traveling to visit family or staying out later than usual -- she may act upset or unsettled.
Communication Skills: It's ooh and aah time as your newborn begins making vowel sounds.
Aww Factor: That first amazing smile turns you into a big puddle of mush.
Fave Toy: A rattle. Your baby loves grasping objects and exploring sounds.
Playtime: Sing-along. Now that your baby is more responsive, she'll whoop with glee at your off-key performance.
Senses: As a newborn, he would only respond to black and white and high-contrast colors. He can now distinguish all the shades of the rainbow.
Body: Your baby is starting to sit with the support of his hands or a pillow. He's also beginning to reach out for objects.
Brain: He's becoming more aware of his surroundings and connecting the sight of things with pleasure -- his mother's face with warmth, the breast or bottle with nourishment.
Communication Skills: Cries are now more deliberate. He may pause between sobs to see whether you're coming to the rescue. He may also cough or squeal to elicit a response.
Aww Factor: Your little one has started giggling, and all is good in your world.
Fave Toy: Bubbles! He'll get a kick out of watching them float through the air.
Playtime: Lay out a playmat or a blanket and scatter toys around. Get down on his level and encourage him to reach out and start rolling or inching toward them.
Senses: Infants are born with a sweet tooth, but by this stage, they've also developed an appreciation for salty tastes, just in time for introducing solids.
Body: Big news! Your baby rolls front to back and probably vice versa, and can sit like a tripod, propped up with one arm.
Brain: She begins to understand the concepts of putting in and taking out.
Communication Skills: By 6 months, babbling begins to imitate speech in tone and pattern. It also becomes language-specific, so a French baby (oui-oui) and an American baby (wah-wah) will start to sound different when they jabber.
Aww Factor: She can see you from across the room now and will probably react with a big smile.
Fave Toy: Plush ball. She's starting to learn how to transfer objects from hand to hand.
Playtime: "Tell me a story." She can focus her eyes and attention better, so make reading a part of your daily routine.
Mealtime: Add cereal, bananas, and other appropriate, easy-to-mush food to your shopping list. The tongue-thrust reflex subsides; your child is now ready to gum and chew soft solids.
Senses: A lovey rules just about now -- the familiar feel and smell of a treasured blankie or teddy is reassuring.
Body: Your baby gets up on his hands and knees, rocks back and forth, and may even crawl.
Brain: Your infant has a crude understanding of cause and effect -- for instance, if you let go of something, it will fall.
Communication Skills: He responds to his name and probably looks up when you say "No!" Time to start setting limits, Boss. Your baby also whines when you take away a toy or (more likely) a forbidden object.
Aww Factor: He shows enthusiasm and excitement when you begin playing with him.
Fave Toy: Pots, pans, cell phones, remotes -- all things adult are the rage.
Playtime: Peekaboo. He's probably been playing this game for several months, but now he initiates the whole process: covering himself then uncovering himself and acting hysterically surprised.
Senses: Your baby is very interested in touching different textures -- make sure there's nothing hot or sharp in her way, then let her explore.
Body: She pulls up to a standing position and may begin cruising along furniture.
Brain: Around 9 months, separation anxiety gets stronger (prepare for clinging) as your baby begins to distinguish between familiar and new people.
Communication Skills: Your baby will start to sound out consonants like p and f.
Aww Factor: She realizes she's the one in the mirror and smiles at herself.
Fave Toy: The contents of your low bookshelves. She loves dumping stuff on the floor.
Playtime: Hide-and-seek. Crawl out of baby's sight and then pop out -- she'll giggle like mad!
Mealtime: She's ready to experiment with feeding herself, so give her finger foods like Cheerios and tiny chunks of apple.
Senses: Your baby's very interested in different scents, so introduce him to a sweet flower or the whiff of freshly baked bread or cut-up lemon.
Body: Prepare for a workout. Your baby will start standing alone for a few moments (before getting freaked out), then take his first step, his second -- his one-thousandth.
Brain: He understands symbolism: He realizes "mama" stands for you and pointing means "get me that, stat!"
Communication Skills: By his first birthday, your baby has a couple of words down and is officially the boss of you. He responds to simple directives like "Wave bye-bye."
Aww Factor: Chances are "mama" and "dada" were among his first words -- yes, you rock!
Fave Toy: Musical instrument. Greater motor abilities and control mean your little one is ready to bang a drum, shake a maraca, or tinkle on a xylophone.
Playtime: Dance party! Your baby can move and groove.
Mealtime: If at first you don't succeed... Keep offering foods he spat out the first time. Research shows it may take eight to 15 exposures until a baby likes a new taste.
Sources: Catherine Forestell, PhD, research associate at the Monell Chemical Senses Center, in Philadelphia; Susan Hespos, PhD, cognitive psychologist at the Infant Cognition Lab at Northwestern University, in Evanston, Illinois; Andrea Thau, OD, spokesperson for the American Optometric Association; Mark D. Widome, MD, professor of pediatrics at Penn State Children's Hospital.