Experts say you can begin signing with your child as early as 6 or 7 months, but it will take at least another two to three months before you see results -- your baby signing back to you.
However, it's never too late to start -- or too early. Sarah Landis, mother of 14-month-old Amelia, has used the signs for "eat," "milk" (nursing), and "more" from when her daughter was a newborn. Landis had picked up the signs from taking her older son to baby sign language classes. "Amelia was signing by 6 months," Landis says.
You don't have to put special time aside to teach your child signs. All you have to do is make the gesture whenever you say the word in your day-to-day routines. The key is consistency and persistence on your part: Every time you give your child his bottle, say the word "milk" and do the sign for "milk."
You can find signs to use on Web sites, by taking a class, or through a book or video, such as Baby Signs by Linda Acredolo, PhD, and Susan Goodwyn, PhD.
Many programs use signs based on American Sign Language, the language taught to the hearing impaired. Others use made-up signs. It doesn't matter which system you use or even if you do the signs exactly as pictured. Modify them according to what works for you (kids will often come up with their own versions anyway!). The only important thing is that you and your child understand what they mean.