So at 13 months, my little girl doesn't say many words. She can say mama, her brother's name, dada, papa, and dog, but that's about it. And most of the time, she's not really consistent. And that's why I love baby sign language.
She's cutting her molars right now, which every parent knows is an intense teething marathon. This means she's frequently fussy, and if she didn't know some sign language, it could get pretty frustrating. But, since she does, she's able to do the signs for "teeth" and "medicine" and I know that she is in pain and wants her Tylenol.
It's also nice that she can sign "water" and "nurse", so that I know which beverage she'd like. :)
Of course, baby sign language is very helpful in relation to infant potty training. When she's signing "poop" I know that she needs a potty, and fast! Or, if she's on the potty signing "all done" I know that she's finished doing her business.
Here's what we used to get started with baby sign language:
I really loved Dr. Garcia's Sign With Your Baby Kit, because it included a book with lots of good information and research on the subject. (It also goes into how teaching your baby sign language will not hinder verbal development, and actually will help it!) Included is a DVD that shows how babies really do sign. It also has a convenient quick reference guide of some common signs that you'll want to teach your baby.
I was skeptical before I had my first baby that Baby Sign Language would work, but I have been absolutely amazed at the results!