We began using signs with our son off and on since he performed his very first sign at 7 mos, "waving bye-bye," and thus demonstrated that he was ready to begin learning sign language.
There are basically 2 different methods for signing with your baby: Joseph Garcia's (you're teaching American Sign Language) & "Baby Signs" (you're making up your own sign language). Through the first - Joseph Garcia's system - your little one is actually learning a second language.
The advantages to his method are:
-ASL signs are nearly universal
-many childcare centers are teaching ASL and will reinforce at the center what you are already teaching at home. In other words, you won't have to teach every teacher or different caregiver, relative, etc. the special "Baby Signs" that you and your baby have created to communicate.
-There are a lot of supplemental materials with this system as well -like videos to watch with your baby, cute little posters at teacher-supply stores, books to read and practice signing with your baby, and even flashcards (I highly recommend using supplemental materials).
On the other hand, the disadvantages are:
-You, the parent, are also learning a new language and it is very time-consuming to study these signs (you really have to dedicate yourself).
-Also, some ASL signs are simply too complex for babies to learn...
Which is why "Baby Signs" was created. This is a method where you basically "wing it." You can either use the suggestions for signs offered in the book, create your own, or follow your baby's lead when he invents a sign, but you're supposed to be consistent. The advantages to this method are:
-They are much easier for baby to learn - so you wind up communicating faster with them.
-Also, during those spontaneous "teachable moments," you can create a sign right then rather than running over to your book or looking online for the sign and totally missing the opportunity to communicate right away.
However, the disadvantages are:
-Baby Signs is relatively new so very little supplemental material exists (I think there may be 1 video in the works right now and a few books).
-Nobody else will know this language that you and your baby have created -so if you want caregivers & relatives to understand your baby, you will have to teach each and every person.
-Your child will just be learning how to communicate with you temporarily and will not be learning a 2nd language that can be used for life.
We began teaching our son "Baby Signs" (with the Baby Signs book) and switched over to the Garcia method when we realized that our son would eventually be attending a daycare staffed by teachers fluent in ASL. We also realized that when ASL signs are too complex for babies, they will create their own easier version anyway and eventually develop the ability to form the proper sign -you just have to pay careful attention to what they're doing. Sometimes, what you think are random hand motions, are really their attempt at a sign of which you introduced to them the previous week;-) The Garcia video is a superb introduction to signing with babies, 100x better than the "Baby Signs" book we read. I HIGHLY RECOMMEND purchasing this kit as early as you can, preferably months before your baby reaches the 6-7 month mark, but remember: it is never too late! The video is the best place to start because you'll have the opportunity to see babies doing their various versions of signs -so you'll know what to look for. After the video, you'll need some sort of reference book that illustrates signs. The book & reference chart, included in this kit are decent. The book includes an intro on sign language and a small dictionary w/ illustrations of common signs. Though we found the book's explanations for signs somewhat confusing at times, we visit
the ASL online dictionary to see an actual person performing the sign. http://commtechlab.msu.edu/sites/aslweb/browser.htm
There are literally dozens of books, videos, and other materials for sale on Amazon that you might also consider. The Signing Time video series sets 1-6 (for babies to watch) and the Sign Babies ASL flashcards sets 1-4 are bestsellers.
Hope this helps!!!