The OT has mentioned it in her report this time. I brought it up in our workshop this time as well. We are getting her interested in ipad and will take it from there. We have a few words and she is 4.5 / so we are still in denial/hope of getting some speech. PECS isnt working yet (this is one point that school, SALT, ABA team and I agree on LOL!)
The book I linked to earlier has quite a good list of words ( it is probably available as a paper copy as well as Kindle, although I've got kindle on ds's ipad, so thought it would be better on there).
Ds is 3.8, his SALT thinks that AAC and signing will be the way to go for him, so we have an appointment with an AAC SALT soon. He is non verbal, his expressive speech has been assessed as between 0-5 months.
There is a free app on the ipad called grid player, which is a tiny version of one of the big AAC apps, you could look at.
salondon, the site you linked to is a US one, their sign language is different to ours Makaton stuff can be quite pricey but it is based on BSL so it might be worth looking at the book hazey linked to or the dictionary by the same person, I've found the Cath Smith books the easiest to get on with. There's also forest books for all things sign.
It might be worth finding out what signing system is used in your locality. Our SN schools use sign-along. Both sign-along and Mackaton are based on BSL (no syntax tho, and they obviously include the spoken word). Be mindful of the Internet as a lot of searches throw up ASL.
I like Family Sign Language as you can watch a clip of someone doing the sign rather than trying to work it out from a diagram. It is BSL, but, as others have said, in the Early Years there is MASSIVE crossover although some people get all uppity about it.