Any experience teaching sign language to a baby?

We started signing with our daughter when she was around 6 months. We weren't really doing it consistently. It was more like when we remembered. We started with eat, milk, more and all done. She started signing back at about 10 months, though babies do understand it for awhile before they are able to sign back. Now at 12 months, she's been picking up more signs, mostly to do with food and eating.

I have the book "Baby Talk" by Monica Beyer. I found it pretty good. It has tips on when to use signs and is easy and understandable read.
http://www.amazon.com/Baby-Talk-Guide-Language-Communicate/dp/1585425176/ref=pd_bbs_sr_2?ie=UTF8&s=books&qid=1200096520&sr=8-2

I also used the internet though. You can find out any sign you want to use. Just search for ASL and the word you want to sign.
http://signingbaby.com/main/?cat=21