Learn baby sign language. Several books and online courses exist to teach you signing for babies. My Baby Can Talk offers several books, DVDs and online videos to help you learn the basics of communicating with babies. Wee Hands offers classroom training in many areas around the United States. (See resources below.) Many of the companies offering instructor certification are geared towards people with no experience or training, but it is possible to gain more from the instructor training if you are already familiar with signing.
Check to see if there are any instructor training programs available in your area. Sign 2 Me offers a mentor program, but no certification, while other companies hold large training seminars a few times a year.
Choose an online certification program for convenience. There is no one standardized certificate program, so each school offers its own certification programs. You do not need any special prerequisites or qualifications to enroll. If you have interest in teaching at a specific school or in a program, you should discuss what type of certification is accepted by that institution before paying for a certification program. Some programs, like Kindersigns and My Smart Hands, offer training, but no formal certificate, while others like Baby Signs have a certificate program. (See resources below.)
Take the courses provided by the program, which will outline the signs, provide examples of course design and teach you songs and other activities that you can use when teaching. Take note of the activities you enjoy, so you can incorporate those into your future lesson plans.
Practice your sign language and activities with babies. Before you apply for work as a baby sign language instructor or start your own business, you should practice on babies and adults. While a certification program may teach you the basics, it will not provide the experience and the confidence needed to make you a good teacher.