Advice on reading material

Hello,

Our 6.5 yr old son has recently been diagnosed with non-verbal learning disorder/aspergers.  I have been looking for a couple of books, one to help my husband and I understand a bit more about these conditions and how we can help our son, and one to help our 9 year old daughter understand her brother a bit more.  I've had a look on google to search for such books but the number available has overwhelmed me.  Can anyone recommend any?

Many thanks,

K.