1) Sit down and have a conversation. - Our lives have become so busy and so full of gadgets and to-do lists and errands to run. I'm afraid that it has caused us to reduce the attention we give to our babies. They have no choice but to lay where we lay them and to look at whatever is in the direction their head is facing. My advice is to put down the ipad or the TV remote or the laptop and put your baby on your lap. Look at each other in the eyes. Practice eye contact. Try to get your baby's attention by making noises and having her turn her head. Then smile. This is also establishing turn-taking skills. Did you know that when you are making noises at your baby that you are teaching them the skill of turn-taking? They make a noise - then you make a noise, then they make a noise, then you make a noise. It should sound just like a conversation with different noises and different intonation, except that it's just gibberish. Gibberish or not - it's still very important!
2) Respond to their vocalizations - More specifically, if you and your baby are in the same room but you're cooking dinner or working on the computer and your baby makes a loud noise, you can probably tell that they are trying to get your attention. Reward it! You want to reinforce the concept that they can initiate conversation and that by making noise they are causing you to turn your head and give them attention. Just take a few second to turn your head towards them. Smile. Make a noise back. Then go back to what you were doing. Not only is it good for language - it reminds the child that you are there for them and that they are the more important than whatever else you're doing at that moment.
3) Tell them what you're going to do, then do it - Talk to your baby all the time. Don't worry if they don't understand everything you say. There is no need to simplify your language at all. Most of what babies learn is 'incidental' meaning as it happens around them and in an unstructured setting. You want your child to be able to associate what you are saying with what is going on. So if you pick up your child and say, "It's time for your bath!" then you get distracted and start folding laundry, they won't learn the association between what you say and what you do. A great example of this is when parents say, "Night-night" as part of the bedtime routine. The baby has learned to associate sleep with the words 'Night Night'. These are the babies who might get very upset if you say 'night-night' to them and they're not tired! :)
4) Nursery Rhymes and Finger Plays - There's a good reason why nursery rhymes have been around for so long. They are a great way to establish language basics in babies. Some of the skills you are reinforcing include: turn-taking, joint attention, eye contact, intonation, and vocabulary. It doesn't even matter what you're singing. Pick a song and sing it to your child. Help them do actions such as clapping hands and raising them high into the air. They'll soak it up.
5) Read to your baby - It's never too soon to start reading to your baby! I've mentioned before some of the great benefits of reading. Big thick board books are great for those chubby little hands to hold and feel. They will associate reading a book with you and the physical closeness and comfort which will help them enjoy reading as they get older. Check out this video of my 3 month old niece! Her daddy is reading to her in Spanish and she is just soaking it up.