I've just started weekly classes with Sing and Sign. My baby is 9 months and I've not had any signs back yet although he does wave his hands about a lot, so maybe he's trying to say something! I'm really enjoying the classes and learning the signs, but to be honest he gets a bit fidgety and I do have to take toys along to entertain him for the hour long class. The songs are really for the parents to learn the signs, although they do mix it up with instruments, toys and background music. If he was a bit older or a bit more placid he might get more out of it. I paid £50 for a course of ten classes.
I recommended three of my friends and received a £5 voucher for each which enabled me to buy the first DVD, and this I would really recommend. It's about half an hour long and we watch it together, it has a lot of the songs from the class on it and contains lots of signs. It's basically a video of a class and there are lots of babies, animals and transport to look at too.
I'm not sure whether to continue with the classes next term, but I may buy the next DVD and just continue with the signs at home. There are also a variety of vocab books, I think that you can buy them direct from the website.
I think that there are some small differences between the signs that are used in different classes, but as long as you're consistent then it won't matter. I think that the main ones e.g. eat, drink, more etc. are the same.
There are also some websites with lots of free content, www.itvbabysign.com is one and also on the CBeebies website under Something Special. They have videos to show you how to make the signs.
Some of them offer a free first class if you wanted to give it a go and see what it was about.
I'm hoping that the signs will be useful to tell me what my baby wants, but I'm also hoping that it will be good for him to get his little brain ticking learning signs for animals and so on.